There are numerous accessories that are especially adapted for use with a standard pick-up truck, the most common including a bed liner, a cap, a tonneau cover, a utility enclosure and a camper body. The utility enclosure and the camper body involve structures which are intended to fit into the bed of the vehicle, between the wheel wells, and provide access to the interior thereof via a door or doors at the rear end. The vehicle operator can enter the enclosure or camper body to obtain equipment or to eat or sleep as is necessary. A camper body can be outfitted with all of the amenities of home, just like a travel trailer, although the interior is rather cramped and is best suited to one or two occupants at a time. A camper body is very heavy and a great deal of care must be exercised if one wants to remove the body from the bed of the truck so that the truck can be put to other uses. Similarly, a utility enclosure is quite heavy, and once it is inserted into the bed it is likely that it will not be removed therefrom without there being a specific need to use the truck with its bed exposed. A utility enclosure is, in essence, a larger version of a truck cap, and it will usually be filled with tools and other equipment.