An apparatus for a vehicle is provided. The vehicle generally has a front wall, two side walls, a truck bed, and a tailgate that altogether define a tonneau. The apparatus includes a tonneau cover that has a front panel and a rear panel. The tonneau cover is slidable along the side walls of the vehicle to move between a closed position and an extended position. In the closed position, the tonneau cover substantially covers the tonneau. In the extended position, at least a portion of the rear panel overhangs the tailgate exterior to the tonneau. The tonneau cover is securable in at least one of the closed position and the extended position.