Any time you change to an aftermarket part, there is a chance for problems concerning your warrantee.
Look at it this way - If you change your exhaust, and later have drivability problems (engine misfiring, etc.) the dealer is going to suspect the exhaust. You may have to duke it out with the dealer to change their mindset. Technically, a warrantee cannot be voided only on the grounds of having the aftermarket part installed. However, if the aftermarket part is suspected of causing a failure, then the warrantee can be voided. In real life, we know that an aftermarket part is going to be one of the first excuses for a problem. It's you against the dealer.
I don't recommend aftermarket exhausts or intakes for two reasons. One, don't expect any real performance gains. If you want more noise, they will do the trick, but that's about all you will get. Two, the hassle factor with the dealer is not worth it to me. Again, only you can decide if it is worth it.
Klaus
Rare 2003 H2 with UM8 Integrated Navigation Radio
Skull & Bones Member since 2003