I noticed recently that my 2005 e46 coupe had a few bubbles appear on the rear wheel arch under the paint. As the car is only 8 years old I thought it was a bit crappy that its corroding already. I had a quick check online and read that it might still be covered under warranty. My car never came with the original manual so I'm not sure what my stance is. Have any of you guys had any luck with this kinda thing? I took it to BMW and the guy took a pic and details and said he'll get back to me. Is this a common fault?

Had this on mine.. Easy fix! Once the rust is cleared up, make sure that just behind the wheel arch, all the mud and road crap is cleared from the little ridge. If you run your fingers up the inside of the wheel arch you'll discover there is a fold in the steel and this is where crap likes to build up, and when it gets wet it can start corroding your paintwork. Mines 2001 and is only just starting to rust. When you clean your car put your hosepipe on full jet and spray this inconvenient part of the wheel arch and use your hands to pull out the crap (very messy the first time!) a quick spray after this each time you clean your car should keep it clear there after! Not sure on how long paintwork warranty is though.. Hope it helps!