Aftermarket parts are replacement parts made by other than the manufacturer. Installing aftermarket (or counterfeit) parts will void your vehicle’s manufacturer’s warranty which will decrease your vehicle’s value and can negatively affect your car’s performance. David Zuby, Chief Research Officer for the Insurance Institute for Highway Safety, cautions drivers about using aftermarket parts saying, “you can’t willy-nilly change those parts because the system may not work the way it was designed.”