According to the Magnuson-Moss Warranty Act, a vehicle manufacturer cannot void the warranty of your vehicle due to an aftermarket part unless they can prove that the aftermarket part was the cause of or contributed to the failure of the vehicle (15 U.S.C. 2302 (C)).

This means that a vehicle’s warranty cannot be “voided;” the dealer can only deny a claim if the stock part failed due to damage or unreasonable use.


When accessorizing your vehicle with aftermarket parts, your warranty claim cannot be automatically denied, nor can your warranty be voided, if you install non-OEM parts in your vehicle. The burden is on the dealer to prove the aftermarket parts caused the failure. For example, if your windshield wiper motors fail, your vehicle’s warranty claim can’t be denied because you installed aftermarket windshield wipers that are different from OEM (Original Equipment Manufacturer) parts. Similarly, if a wheel bearing fails or a fan belt snaps and you have an aftermarket exhaust installed, the dealership would have to prove the exhaust system caused the bearing failure or the belt to snap in order to deny a warranty claim. In these types of scenarios, the dealership should have no reason to deny your claims.


In addition to the Magnuson-Moss Warranty Act, you also have SEMA (Specialty Equipment Market Association) working to protect your rights. Because SEMA represents U.S. aftermarket wholesalers, retailers, distributors and manufacturers, they often keep car manufacturers in check by supporting legislation that prevents dealership service providers from denying warranty coverage.