It's a constant battle to keep that salt off the undercarriage and with the sound insulation under the LS, I wonder if I'm doing more harm than good by spraying water under there to rinse the salt off. I think I may be making matters worse and I'm kind of pushing the salt up and through that insulation.

Some friends of mine recommended a product called Fluid Film - and I've been using it for two years - but I don't know if it helps or makes matters worse. It's pretty sticky stuff and I wonder if it just traps more salt and sand...kind of lodging it in there. I only spray it on the pinch wells and exposed metal....I don't remove the sound insulation pieces and spray under them.




What are your thoughts on the undercarriage insulation that covers the bottom of these cars? Does it protect, or does it trap?

 

I'm in southern Ma, but my car is from up around the Portland area. I don't even think about it. Haven't seen anything excessively rusty about my car vs others. Not worried.

 

Yeah but don't you drive like only 30 miles a week or something? Was it you, or someone else that had a 7 mile commute to work?

I guess it's just a car, I shouldn't care, but I've lost a few to rust and I'd like to prevent it this time. Probably impossible up here, but I'm not going down without a fight this time. A friend of mine just bought a southern car, you should see how different it is under a southern car...they look new.

 

Unfortunately i am in the salt belt as well. To be totally honest, I've never done anything specifically for my undercarriage. I'll have to sprayed down every now and then. but that's it. I'm pretty sure they metal they use is already coated in anti rust/corrosion chemicals so it really shouldn't affect things too much.

Personally, I put a lot of my time into the actual paint work on my car. Always a 2 bucket wash system, with a mild shampoo and some sort of protective spray/coating afterwards. Idk how much of a difference it makes, but I always clean door jambs and inside the gas cap to prevent water from acculumating and potentially causing rust long term. I know when I sold my 430 there was not a spot of rust on her and the paint still looked great (even though I was away at school and didn't wash properly all the time ). Also, I can say that despite me doing a minimal amount to the undercarriage, I did not notice any loss in sound deadening, as she remained extremely quiet and I ended up selling the car for a high (but fair) price.


Just for fun, here are some shots of the 'ol girl. Keep in mind, this was an 04, pics taken summer of 2015 for my ad on Autotrader. It was a Chicago car prior to my ownership, and I drove it mostly in MI which gets all sorts of nasty stuff on its roads.

 

I use FF on all my snow equipment (plow, spreader, ATV, snow shovels & blower) however I do not use it on my cars..... This stuff is excellent!
I wash my cars on a regular basis and rinse the under carriage off with salt x www.saltx.com (after a snow and salted roads) and have no major rusting on any of my cars. I never use a pressure washer because the pressurized water can "push" the brine into tiny nooks and crannies on the car where it can't drain out.
I am a big fan of Adams invisible under carriage spray for looks and protection. www.adamspolishes.com and use this all year long....... Any other brand like Chem Guys, Griots, etc. works well too!
I keep the cars detailed and try to wash them once a week...... Weather permitting.

 

Checked out the website...looks like they have some nice stuff for reasonable prices, but I couldn't find the undercarriage spray you mentioned.

 

I live in the salt belt AND have about a quarter mile of rutted, often muddy gravel road to cover to get to my house. I hate how much salt and mud I get stuck under my LS all the time. I have a leased pickup (Dodge Ram) that I generally drive when the snow or mud is especially heinous. There are times in the winter when I don't drive the LS for weeks at a time.

One time I noticed one of the sound insulation panels under my car was drooping. I asked the Lexus dealer to check it out during an oil change. They came back and told me there was like 30 pounds of sand/dried mud stuck under there weighing down the panel! Not good for the car, I'm sure!

Oh well, such is the price for living in Nebraska!

 

My commute is about 2 miles to work, but I do take it on trips during the winter all the time. When it is snowing out though I use my "other LS". Its a 2002 Chevy Astro LS van AWD. That thing is absolutely amazing in the snow. One of the times we got 2 foot of snow, I put it in drive and drove down every unplowed street without issue. Even took it deep in the woods and it had to plow a path with the front end thats how high the snow was.

 

Invisible Undercarriage Spray..... View under exterior products or just search for the product on the Adams site. Chemical Guys also has it under the name Bare Bones Undercarriage Spray.
If you decide to use this I suggest buying a gallon because it goes fast.

 

I never heard of Fluid Film until just now, so I can't comment on its effectiveness. However, I can comment on what I think the issue may be. My wife had a 1995 Infiniti J30t, and I had a 1995 Infiniti Q45a (one of the best cars I have ever owned). Both cars met their demise because of excessive rusting of the undercarriage, body panels and other exposed components. Keep in mind every winter I would bring out the hose after particularly salty roads and wash down the undercarriage.

Now my wife's Jag is turning 15 years old and my LS 460 is over 8 years old and there is not a hint of rust anywhere. Again I bring out the hose after particularly salty roads and wash down the undercarriage. I have to think it is a function of how the manufacturer treats the body during the manufacturing process. I have a long term mechanic who has serviced many of my cars. He told me that Nissan products are the worst for resisting rust.

Based on my results with my current cars, I am not going to do anything with them. However, if I had this info back when I had the Infiniti's, I would have tried anything.

 

You bring up a great point regarding Nissans, I totally agree that they are the worst cars I've ever seen concerning rust...they rust...and they rust bad. It's not uncommon to see radiator supports completely missing - I mean gone - because of rust...the radiator is being held in by the hoses. I've had many friends expecting to keep their Nissans for the long term, only to have to trade them in do to corrosion. Honda isn't much better.

As for my LS...it was previously a Florida car, but after a few years in New England, I am seeing some rust forming on the undercarriage...which is normal, I just don't want it to turn into my Honda. This is my second year using the Fluid Film, I have no idea if it's doi anything, probably not.

 

Toyota pick up trucks have a major chassis rust problem....... There is a Toyota dealer (off site shop) near me and they have 3 guys doing a full chassis replacement on these pick ups every day all year long. Toyota has a recall on them so the rust issue is not just isolated to Nissans. I feel if you hose off the underside of your car and make sure you get the "brine ice bergs" out of the wheel wells will help with preventing major rust.
I see rusting on various make of cars/trucks where dirt gets trapped like near mud flaps, running boards or any areas where the water cannot drain..... The sad thing is rust occurs on many different manufacturers and models in the same areas. EG: All Ford Crown Vic's rust on the upper front fenders.
I did look at older model (unmaintained) LS's and they seem to hold up well as far as body rust so that is why I was attracted to them. The neglected body (by previous owner) on my sons '97 ES is rust free but the underside is very rusty but not rusted through so I feel a 19 year old car (with 240k. miles) that was not maintained by regular washings/waxing has held up well over the years of harsh NJ winters so I feel Lexus does not have a rusting problem compared to other makes and models.
For anyone that has some rust forming there is a "rust/corrosion stopper" from the makers of PB Blaster that works well www.blastercorp.com this is not a rust converter (like POR 15) so I suggest if you have some rust forming spray some rust stopper in the area to at least slow it down. Eastwood has some rust proofing chemicals on their website too. www.eastwood.com

 

Interesting points. Does anyone on here actually have, or know of someone with a 460/600 that has a rusting problem? I would like to think all the metal that goes into our cars are pre-treated from the factory (?)

 

While looking for my car I had a look at a couple of 2007 and 2008 salt-belt cars. They had no apparent rust anywhere, although I couldn't see past the underbody fairings. These cars seem pretty rust-resistant.

Salt-belt cars had other issues, though -- a lot of yellowing plastic on lights, badly abused carpet, and failing rubber seals. I ended up buying a car that spent its whole life in California, and my second choice had spent its whole life in California or Arizona.

 

Good to know! Yeah I never came across a rusted 460 either. I would've loved to have a CA car, but distance restricted me, and did not feel comfortable buying sight unseen. My 460 came from WI, but was pretty clean with low miles so I'm trying to do as much due diligence as I reasonably can to keep her looking good. I hear ya on the carpet part - right now I use weathertech mats, but they dont cover the footrest area well so I have a ghetto piece of cardboard protecting it lol. I try not to open my driver's door when there's a lot of people around