Carrot Top and an Aussie beefcake troupe known as Thunder from Down Under pass for culture in the devil's den of Las Vegas. We skipped both. Passed on Penn and Teller, too, and although "wacky, avant-garde, percussion-driven entertainment from blue-hued performers" sounds freakishly tempting, we blew off the Blue Man Group.

Instead, we drove the 2007 Jaguar XK8 Coupe and 2006 BMW 650i Coupe from L.A. to Vegas to visit the Neon Museum, which doesn't really exist, but we're told it will. Plans call for an exhibit gallery, research library, store and café along with classrooms and banquet facilities. In the gallery will be refurbished neon signs, a classic Las Vegas art form, from the past seven decades.

Until funding for the above is donated through loopholes in the tax code, you can tour "The Boneyard," a couple of sizable dirt lots north of the Strip. The Louvre it ain't. Both lots are surrounded by 8 feet of chain-link, but beyond the fencing are more than 100 unrestored signs and bona fide Las Vegas culture, if there is such a thing.

Why drive two $80,000 luxury coupes 300 miles to a neon graveyard? Because it beats walking to one, that's why. Plus, the all-new 2007 Jaguar XK8 and the bigger-engined 2006 BMW 6 Series would look oddly out of place at some seedy massage parlor.

Too-cool coupes
Long hood, short deck, two doors and a fixed roof. It's a design as timelessly desirable as Steve McQueen and the banana split. Only sadomasochists and mothers of septuplets fantasize about additional room for the kids. Sure, there have been some epic sedans over the years, but the car of your dreams, the one you stay up nights lusting after, the one you secretly shop on eBay for while the wife's asleep, surely has two doors.

These two rear-wheel-drive coupes are certainly worth a few late-night lust sessions. The BMW 6 Series, with its acquired-taste style, has been around since 2004 as the 645Ci. For 2007, it's been given a shot of the same stuff that's made Barry Bonds such a home run machine. BMW has replaced the car's 325-horsepower, 4.4-liter V8 with a 360-hp, 4.8-liter V8 and changed its name to 650i Coupe. Although a six-speed manual is available, our Alpine White example had a six-speed automatic transmission. It also wore the Sport Package and a few other sundries that drove its sticker price up to $79,840.

The Bimmer's additional muscle is fortuitously timed, because of Jaguar's complete redesign of the XK8. The 2007 version of the sexiest cat is sexier than ever and powered by a 300-hp 4.2-liter V8, also backed by a six-speed automatic. A few options, including the $8,125 Luxury Aluminum Package, took its as-tested price up to $86,460.

Aside from the 750-mile round-tripper from Santa Monica to The Boneyard and back, we lived with these two leather-lined two-doors for 10 days. They endured everything from heavy-metal romps through the Malibu mountains to hard-core slogs through some of the nation's worst traffic. We even made some of our friends ride in their ridiculously small backseats. Sure, we laughed as they shoehorned themselves back there, but automotive evaluation is a serious business and the risk to decade-long relationships was worth it. Oh, and we also took them (the cars, not our friends) to the test track, which was also fun, but not as funny.

Still the ultimate
After all that driving, laughing and testing, we crunched the numbers, asked ourselves which one we would spend our cabbage on, and chose a winner. Although we would like to say it was a tough call, it wasn't. The 2006 BMW 650i Coupe took this one by several car lengths.

It's not that the Jaguar is without appeal. This is a drop-dead gorgeous machine that performs well and offers high comfort. If its lines have you in a magnetic tractor beam, write the check. This car will make you happy.

No one would call the 650i drop-dead gorgeous, although its profile has caused a few passers-by to actually drop dead. The Alpine White paint didn't do our tester any favors either. But the BMW performs much better than the Jag, costs less than the Jag, is quieter than the Jag, has a much more usable backseat than the Jag and offers a significantly larger trunk than the Jag. It's also more comfortable, more refined and built with superior fit and finish.

In the end, it's that unique depth of engineering that gave the BMW the win. She may not be all that much to look at, but, boy, she sure can cook.

We admit to leaving the 2005 Detroit Auto Show uncharmed by the look of the 2006 Jaguar XK8. Too much like an Aston Martin, we said. Make that an Aston with Chevy Cavalier headlights. But we were wrong. Must have been the lifeless Robin's Egg Blue they painted the concept car, because this car is hot. Paris Hilton eating a messy hamburger while washing a black Bentley hot.

Out in the real world of beige Camrys, the Jag's voluptuous curves stand out like Hef's girlfriends. On the way to Vegas, people actually pulled alongside and snapped pictures of the car, paparazzi style. Now we know how Britney feels. But the Jag is more than just a sexy bod. Although Jaguar got a few details wrong and the 650i is the winner of this test, the XK is one of the best driving cars we've ever driven, and a vehicle we would be proud to own.

New chassis, old engine
Beneath that beauty is the most technologically advanced Jaguar ever, so says Jaguar. Like its XJ sedan stablemate, the XK is now constructed mainly of aluminum to save weight and improve the car's power-to-weight ratio. Everything from its structure to its body panels is made of the stuff. As an example of the materials weight savings, Jaguar says the XK's aluminum doors are each more than 13 pounds lighter than the equivalent steel door.

Under the Jag's reverse-opening hood is a 4.2-liter double-overhead-cam V8 also constructed entirely of aluminum. Unlike the chassis, however, it's essentially carried over unchanged from last year's model. Peak power is up slightly from 290 to 300 horsepower thanks to a little fuel-injection fine-tuning, but that's still 60 hp less than the BMW. Its peak of 310 pound-feet of torque is also on the light side and occurs at a lofty 4,100 rpm.

Aside from a recalibration for quicker and more positive gearchanges, the Jag's six-speed automatic is also the same transmission the company's been using for a while. Jag also replaced its trademark J-gate with steering-wheel-mounted paddle shifters.

Not really quick enough
Despite all that use of aluminum, at 3,759 pounds, our Liquid Silver XK8 was only 139 pounds lighter than the significantly more powerful 650i. Plus it carries a higher percentage of its weight over its front tires than the BMW does, which seldom translates to superior handling.

Do the math and you would expect the BMW to outrun the Jag, and it does. From a standing start the Jag hits 60 mph in 6.4 seconds and covers the quarter-mile in 14.5 seconds at 99 mph. Not exactly slow, but quite a bit slower than the 650i, which hit 60 mph in 5.6 seconds.

On Main Street, the Jaguar feels quicker than it is, due to the engine's quick throttle response and pronounced V8 soundtrack. As much as we like the Jaguar's smooth V8, it's the car's six-speed transmission that stands out. Although it upshifts at 6,250 rpm despite the tach's 6,800-rpm redline, it's well-geared, becomes truly responsive in Sport mode and matches revs beautifully on downshifts.

Not really athletic enough
Those downshifts are the best part of driving the XK8 in the hills, where the Jaguar feels a bit nose-heavy. The latest version of Jaguar's Computer Active Technology System (CATS) manipulates the XK's four dampers separately, which allows control of roll as well as pitch. Stability is exceptional, but the Jaguar feels large when you start throwing it around and understeers more than we would like, which keeps it from being as tossable as the better-balanced BMW.

Even with the standard electronic stability control deactivated, there's too much traction at the drive wheels, which exacerbates the XK's predisposition toward push. Our car wore optional 20-inch wheels and tires, which look fantastic, but are really just too big for the car. We wonder if the Jaguar is better balanced and more responsive to driver inputs on the standard 18-inch rubber.

At the test track, its 0.82g of lateral grip on the skid pad and its 66.6-mph speed through our slalom were both beaten by the BMW, which rides on smaller 19-inch tires. Plus, the BMW rides better, with less impact harshness than the Jag.

Like the rest of the XK's dynamics, its braking is excellent; it's just not as good as the BMW's. This big, heavy car stops from 60 mph in just 120 feet, and its ventilated four-wheel discs resist overheating as well as any brakes we've ever tested. The BMW, however, stops in 112 feet with similar heat resistance and a firmer, more immediate pedal feel.

Flying first class
You sit low in the XK behind a leather-wrapped three-spoke steering wheel and a couple of chrome-rimmed gauges. Jaguar kept things simple with white-on-black instrumentation, a minimum of secondary controls and a smattering of tasteful chrome. Everything is dressed in leather.

The new dash may not be as distinctive as the one it replaces, but its ergonomics are well thought out and the driving position is very good. Jaguar puts the electronic push-button for the parking brake by the shifter where it belongs, and supplies two cupholders, which can be hidden away in the console when they're not needed. You fire the engine with a red start button on the console.

Problems are limited to the Jag's Driver Information Center Display, which the carmaker brags can display 256 colors and features Thin Film Transistor Technology on its 7-inch touchscreen. The problem is the screen's insensitivity to touch, however. Several prods of the finger are needed for most requests, and then the system seems to take forever to change screens or functions. Switching from AM to FM radio, for example, is not only needlessly distracting for the driver, it can be maddening. Although we still prefer it over the BMW's sinister iDrive system, it's only marginally better.

Just for two
Seat comfort is high. We made it to Vegas and back without one sore back or whiny complaint. And the Jaguar has a surprising amount of room up front. Although a sunroof is not available, which seems odd in this class, headroom can be limiting, but Jaguar has added a couple of inches of seat travel and legroom.

Long, low and wide, the 2007 Jaguar XK8 Coupe is 6.4 inches longer and about 3 inches wider than its predecessor, which was introduced way back in 1996. Although that makes it 1.5 inches wider than the BMW, it's all in those bulging hips. From inside, the Jag is about the same width as the 6 Series.

The XK's 108.3-inch wheelbase, however, is about an inch shorter than the BMW's, and the 650i is more than 2 inches taller. These two stats translate into more rear-seat headroom and legroom in the BMW. Enough for its backseat to be usable, whereas the Jaguar's is there for…well, we're not really sure why it's there. Plus, it's fixed in place. Jaguar would have been better off making the seat fold down to take advantage of the XK's hatchback body style and expand its limited 10.6 cubic feet of luggage space. The BMW features a pass-through for long items like skis and rain gutters, and its trunk is larger thanks to its carbuncular deck lid.

Our Jag was also peppered with a few quality issues, including paint-color variations from panel to panel and irregular panel fits inside and out.

So it comes in 2nd
Jaguar has built a brilliant piece of machinery, one anybody would be proud to pay monthly for, but any car, even one as good as this Jaguar, is going to lose comparison tests when it's more expensive, dynamically inferior and less practical than its competition.

Add in the BMW's superior build quality and there's no denying that the 650i, although not as aesthetically desirable, is the better all-round car. And the better value.

Truth be told, after the run to Vegas we still didn't have a clear winner. Both cars relished the road trip, delivering our unsavory crew to the oasis of sin without backache or busted wallets. Surprisingly, both cars averaged almost 22 mpg on the trip.

Back in Los Angeles, however, further evaluation began to throw points at the less expensive BMW. More time spent behind the wheel revealed its superior performance, refinement and build quality. It's a car as happy to be on the interstate as it is in the city or the twists and turns of Mulholland Drive.

Although some testers are put off by the sometimes synthetic feel of the 6 Series, by the end of the week we all agreed that if the BMW looked like the XK, then Jaguar and the rest of BMW's competition could pack up their tents and walk home.

Same look, new engine
But it doesn't look like the Jaguar, and the BMW's controversial shape is for 2006 as it has been since 2004. Love it or hate it.

The rest of the car is essentially unchanged as well. However, there are a few very meaningful improvements, including a new lump under the hood. Gone is the 320-horsepower, 4.4-liter V8, replaced by a 360-hp, 4.8-liter V8. It uses the same all-aluminum construction and double-overhead-cam design as its predecessor; it's just larger and more powerful. Torque is also up significantly, from 330 pound-feet to 360 lb-ft, and it peaks at a lower 3,400 rpm.

Like every BMW engine we've ever experienced, this new V8 is silken and anxious to rev. Although there's a nice surge of power at the top third of the tachometer, there's plenty of torque available at any rpm. Jump from the 6 Series into the XK, and the Jaguar's smaller V8 seems to rev slowly and feels light on bottom-end torque.

A ***** in the armor
If the BMW's drivetrain has a ***** in its armor, it's the car's six-speed Steptronic automatic transmission. It's geared well, and feels good around town, especially in Sport mode, but in the hills it's reluctant to downshift to 2nd gear for slow corners. Plus, it doesn't match revs on manual downshifts like the Jag's six-speed.

Of course if the BMW buyer wants more control, the 650i is available with two other transmissions, a true six-speed manual and a six-speed Sequential Manual Gearbox (SMG), which BMW also uses in the 500-hp M5. The Jaguar, on the other hand, is only available with the automatic.

With the automatic, the BMW is good for zero to 60 mph in 5.6 seconds and a quarter-mile run of 13.8 seconds at 103 mph, which is quick in anybody's book. It's also quick enough to skin the cat.

Dual personality
Our Alpine White 650i wore the optional Sport Package, which adds well-shaped sport seats and curiously spoked 19-inch wheels. Every 6 Series, Sport Package-equipped or not, gets the same suspension calibration, which BMW says is firmer than the standard calibration on the 550i sedan, but not quite as firm as the suspension of the 550i Sport. We like this do-one-thing-and-do-it-right philosophy, as it has served BMW and its buyers well in this case. Even on smaller tires, the heavier 650i outrides and outhandles the XK.

On the interstate, the BMW swallows miles like a high-end luxury sedan. This car is supremely comfortable and effortless at speed. The suspension's ability to soak up even the largest impacts is astonishing. Impact harshness and unnecessary body movements have been completely dialed out, while BMW has dialed in just enough feel and feedback for this to be a true driver's car.

And this is a true driver's car, one that thrives on a good romp through the hills. Although the BMW's 0.85g skid-pad performance and 66.7-mph slalom speed are only marginally better than the Jag's numbers, the 650i is our preferred dance partner. The harder you drive this car, the lighter and more responsive it feels, but because the 6 Series understeers less than the XK, more talent is required to get the most out of it.

Tech watch
BMW has yanked Active Steering from the Sport Package and has made it a stand-alone option, which our test car thankfully did not have. The standard variable-ratio rack and pinion system, which makes the steering quicker as the wheel is turned, still takes some getting used to, however, and is not without the occasional synthetic feel around town. The good news is how much it comes alive in the hills. In true BMW tradition, the steering wheel and the contact patches of the car's front tires begin to feel fused together.

We also credit BMW's Active Roll Stabilization system for the 650i's athletic ability. The electronically controlled, hydraulically activated active antiroll bars are standard equipment, and deliver truly flat cornering. It's one of the reasons the 6 Series feels so light on its feet.

Some complaints were directed at the BMW's brakes, which can be a bit grabby around town. Like the rest of the car, however, they take on a comforting immediacy as the pace is quickened. They stop this heavy car from 60 mph in just 112 feet.

iDrive aside...
Kill the man who invented iDrive. There, we said it. It's still the most irritating thing ever created by man. Makes the Rubik's Cube seem intuitive.

All else with the 6 Series interior is the same as it has been since 2004, which is to say perfectly assembled, nicely appointed and a little fussy in its detailing. You sit more upright than you do in the Jaguar, and there's an old-school hand brake and an enormous glass sunroof that tilts up only. Comfort is high and unlike the Jaguar's rear seat, the BMW's can actually accommodate humans. Two if they're good natured. The BMW's trunk is also more useful than the Jag's, with 13 cubic feet of space and a pass-through for that flagpole you've had your eye on.

Our test car wore a long list of options including the Cold Weather Package ($750), the Premium Sound Package ($1,800), the previously mentioned Sport Package ($1,800), active cruise control ($2,200), a head-up display ($1000), high-definition radio ($500) and satellite radio ($595) which drove its sticker price to nearly $80,000.

Although that's still $6,000 less than the Jaguar in this test, which had fewer luxuries, our advice is to ditch the the head-up display and high-definition radio. Fact is, we never used them during our time with the car, and it'll shave another $1,500 off the sticker price, turning the 650i into an undeniable value.

Yes, it's still the ultimate
And that's how you win comparison tests as well as buyers: by being less expensive, better-equipped and more fun to drive. As much as we lust for the Jag's bod, the 2006 BMW 650i wins.