Many of them negotiate a great deal on the purchase of the car, maintain the great deal when it comes to the financing, and then breathe a sigh of relief, relax, and get pounded in the accessory department. If you absolutely must have this stuff on your car, buy it from a reputable source, install them yourself, and save a bundle. Dealer added rustproofing may actually void the factory warranty. Paint sealant . The claim will be that this will prevent you from having to wax your car.
Some paint sealants are reasonably decent products.
Many are glorified wax jobs. All are expensive relative to what you will get. Fabric sealant . Designed to protect interior fabric. You can do this yourself with a store bought fabric protector and save big bucks.