What to doIf you have a problem with your modified car, the first thing to do is check and see if there is a Technical Service Bulletin (TSB) for it. These are mandated manufacturer-wide recognized faults in a car model and will be fixed for free no questions asked at any dealership. (Check out our Hotbox for places to find TSB listings.) You'll often need to present the TSB number to your dealership to get the work done.
The next step is to keep a level head, be forthcoming and visit your dealership for service. And above all get everything in writing. If a service writer refuses to cover a repair because an aftermarket part is blamed and you are one hundred percent sure it couldn't have caused the failure, get him or her to write out in detail how the aftermarket parts are directly responsible for the failure. Remember, under the Magnuson-Moss Act, aftermarket parts can only void a warranty if they directly cause the failure; just having them on the car isn't grounds for denial. Don't agree to any labor until the dealership is able to prove it on paper. If the parts did indeed cause damage, the dealership should have no problem explaining it in writing.
If the service writer won't budge on explaining how your cat-back exhaust caused the radio to go out, get the service manager. If he or she refuses to help you, speak to the dealership owner. If he or she refuses, try another dealership. If there are no other dealers around, find the local manufacturer warranty representative; he or she often has the ability to push warranty repairs through at local dealerships. If all of these routes get exhausted, the last extreme steps include talking to your state attorney general's office, the Better Business Bureau or ultimately the small claims court system. You'll often spend more on legal fees than you would pay for repairs, but breaking the bond of a warranty contract based on false allegations is against federal law-and sometimes it's just the principle of teaching a dealership a lesson.
Just try to not let your warranty dispute grow that large, keeping it at the service manager level will prove to be much easier in the long run. If you have an understanding service manager, he or she will see your air intake didn't cause the trunk lock to stop working. According to Ang, "It's annoying when customers come in yelling, complaining and lying about what parts are on the car and how they have been driving the car. We'll find out what you've been doing with it and whose fault it really is." Ang also added, "The golden rule when you want to modify your car but can't afford to pay for repairs is you have to pay to play."
Pay to play. The modern "you break it you bought it" applied to a modified car. Welcome to the real world.