The pickup bed at the back side of a GM truck serves as cargo bay for unwieldy things that seem unfit to go inside the passenger area of the GM interior. These cargoes typically pose risks of damaging the GM interior. They are placed in the cargo bay instead and thus spare the GM interior from scratches and dents. The GM cargo bay, like everything else installed on the car, is made for the chronic wear and tear of rough driving. It is constructed from high-grade steel and can be kept secured by a GM Tonneau cover. Engineered from durable vinyl, plastic, or fiberglass, a GM Tonneau cover is fitted over a pickup truck bed to keep lightweight cargo firmly in place and block out rain, sun, and snow.

GM Tonneau covers are valuable truck add-ons. They do not require snaps, hooks and bows to be fastened to your pickup, yet remain permanently attached to the sides of the GM truck bed. Features of the GM Tonneau cover include a rolled-top cover that operates like a garage door. The snap-down GM tonneau cover is the most popular variety because of its low price and ease of use. Using the snap-down cover is as easy as snapping down the GM tonneau cover when you want to secure your cargo, and unsnapping and rolling it up when you need to carry large cargo or want full access to the bed.

To provide easy access to the GM cargo bay, the entrance to the truck allows for a mounting point to accommodate a GM running board. Called in the automotive industry as Nerf bars, GM running boards are tubular devices fitted on the back and flanks of a GM truck, sport utility vehicle, or other similar off-road vehicles to act as a step for easy access to the vehicle. They are typically constructed from either stainless steel, chrome or powder-coated steel although there are considerable variations in style , color and design. They are also referred to as GM step bars, GM boss bars, GM tube steps, and GM step tubes.

Supported by the heavy-duty steel construction of the GM frame mount brackets, a standard GM running board is designed to withstand weight load of up to 300lbs or more at a time. GM running boards fitted with an aluminum support frame beneath the stepping surface can even carry a weight capacity of up to 500lbs. The step of the GM running board, on the other hand, has an all-weather grooved pad designed to channel water away from the stepping surface. Aside from providing a no-slip surface for stepping, GM running boards also help in keeping dirt and mud away from the vehicle interior.