Coming in late, here, folks, sorry, but I just noticed this topic and the statements made in the first few posts are not accurate. First, I own a 2005 that is WAY out of warranty through mods. Doesn't bother me, since I don't expect warranty coverage after I've violated the terms of the warranty.
This bunk about "they have to prove the modification caused the problem" is total bull. They don't have to prove anything. You don't have the right to modify your car and still expect warranty coverage - it's right in the manual, and you agreed by buying the car and accepting warranty coverage.
One enthusiast to many others, I don't want to steer you wrong like some jailhouse lawyers here have. There's lots of things that can get covered after mods, it's all in how you act and handle the complaint and appointment.
I've been racing cars a lot longer than I was a service manager, so I don't want to see people set up for failure by going into the dealership with an attitude, thinking they have the dealer (and the manufacturer) by the gonads, because you don't.
I'll be glad to discuss things and to help folks get things handled properly, but I won't quote laws I have no clue of (as has been done) and won't blow smoke up your butts. Guiding people, who likely take forum information as the Gospel, without having the facts, is very irresponsible.
Check my profile (website) if you have any questions about why I know what I'm talking about.