Sumthin for the photo choppers
That said, the only RX's that I've seen that look good on rims are also dumped and kitted - that was a nice look, but I'm not convinced the 16" size wouldn't look better even then. SUVs just don't look quite right ridin on that little of tire, plus I don't wanna have to avoid potholes when I'm driving an SUV (which you probably wouldn't have to do with 17s or 18s, but DUBZ? COME ON!)
Part of the problem may also be the type of rims that most people "upgrade" to on a RX - I think a lot of them are too ghetto... I don't like ghetto rims, and much prefer something on the more mild side.
That's probably more than you wanted to know from me - sorry Disco... I'd say get some lowering springs first - that'd definately look good. Also, look at the pics gallery to find other similar examples of what you are talking about - that should give you a better idea about what you want to do.
on the big rim issue, 17" rims are by no means big for the rx....even the 18's don't look all that big. 255/55 tires on 18" rims stiff give you a whole lot of sidewall. i have hit some pretty big potholes here in south texas and have not had a problem yet.
as far as slowing the rx down.......don't think to many people bought the rx for racing. hehe. it is not exactly a fast suv. if your rolling diameter is the same you aren't gonna see a lot of difference. the unsprung weight from a larger rim might.....just might get you. but the factory 16's aren't exactly a light rim either.
You're right on about those IS3 rims - I love those too... Very clean - they're ANTI- ghetto!

I can tolerate up to 18's and might even like 'em - don't wanna spend the money on them though when I'm already happy with my 16's... Plus don't wanna have to swap when the snow comes.
While most people wouldn't buy the RX for racing, it's gotta be jack-of-all-trades (racing, towing, cargo, cruising, etc.), and with that in mind I really wanted a sports car like the IS3, but I'd rather be able to fish and hunt and have a 1-room cabin in the woods than any other amenity in life, so the RX3 was the practical/obvious choice (and the AWD sure is nice in snow). What I'm getting at, is I wanna keep the RX as quick as possible.
Maybe I'm just trying to talk myself out of a pricey mod
Okay, yeah, I can admit it... I've got no $chaching$ for wheels and I'm jealous. Wow, that's better. 
The RX isn't an X5 speed-wise... But I don't know of any other SUV that's quicker - I took a Jeep Grand Cherokee off the line just last night - I thought those were supposed to be quick?



