mikeh

The original post is asking for rust proofing on a new 2010 A3. I am all for rust proofing as long as it doesn't involve body panel penetrations that void factory warranty.

tdenton

My wife has an A3 the body is galvanized not need to drill holes my last A3 got a stone chip above the windscreen and it never rusted in 4years

K04-S4

Agreed no rustproofing needed as body panels are galvanized. For any rust to form, there must be a tear or opening in the body paint that penetrates the galvanized layer. Last I checked Audi warranty on rust thru penetration of body panels was 12 years & unlimited mileage.

Most common to see rust forming is a deep stone chip or nasty door dings that expose the raw sheetmetal and staying on top of Paint Touch Ups helps this issue. Also body molding clip holes and any sharp sheet metal panel edges may eventually show surface rust with higher mileage in high road salt exposure winters etc.

If you want to try and keep your undercarriage bolts / subrames / etc looking newish then as suggested confirm with your Audi Dealer if Rust Check undercarriage spray with no holes or penetrations is acceptable to maintain Audi warranty.

My 02

tml

no to be a smart *** or anything but why do I see b5's with rust??

I'm sure if they have used rust check from day one the bodies on those cars would be still rust free... just look @all the mk4 vw's..all showing rust & they all also so call galvanized!!!

mikeh

How many B5s have you seen with rust? How were those B5s maintained? Where was the rust?

My point being that it is difficult to determine what you have seen regarding B5s with rust and the norm. I am not saying that cars don't rust or there aren't some lemmons out there. I own a B5 S4 and a B7 S4 and both are rust free. I am meticulous when taking care of my cars so that might have something to do with it. As mentioned earlier, rust proofing of any kind is good as long as it does not involve body panel penetrations where the galvanized integrity is compromised.

K04-S4

Rust Check does not get sprayed on the outside of the painted body. Rust Check gets sprayed on undercarriage and if you allow penetration holes to be used then it gets sprayed inside body panels. If the rust you are seeing is on the body panels then the paint and galvanized layer was penetrated allowing rust to form aka stone chips & door dings etc. If the paint is maintained and sealed then rust will not form. Just as Mikeh indicates, all my cars are rust free as well because the paint remains sealed. It's not complicated. Stay on top of paint chip touch-ups and seal the body paint every few years.

mikeh

Thanks KO4-S4, well said.......hopefully we can put this to rest.

tdenton

Galvenized bodies where only introduced in MY 2003 might be out a year

K04-S4

?

Not sure exactly what year they started galvanizing but it was several years before 2003. For example Audi 12 Year Rust Perforation Warranty with Unlimited Mileage applied to 2001's and it had been already established that Audi (and some other high end brands) had good factory galvanized rustproofing by that time.

alphazero

Double-galvanized bodies. No need for rust-proofing... unless you have had extensive body work. Once a panel is hit and "repaired", it's not likely it is going to hold up over the years.

That said, I've owned 2 A4's, both of which were 8+ years old when sold and they were 100% rust-free. And I live in Montreal Quebec... one of the harsher winter cities to live in (yeah, they use sand here with salt... not to mention the egregious potholes).