Auto Add-Ons Truck & Car Accessories. Kingston’s Largest automotive accessory stop. With the most experienced staff in the area, guaranteed great pricing and the best service in the industry. Auto Add-Ons specializes in Trailer Hitches, Truck Caps, Tonno Cover’s, Rims & Tires, Truck Boxes, Utility trailers, Navigation (GPS), Car Audio, Spray On Box Liners and much much more!!!