An inertia-driven dump load apparatus is provided in association with motor vehicles. The inertia-driven dump load includes a container defined by two side walls and a front wall; and at least one pivotable connection means connecting the container to the vehicle bed. To operate the inertia-driven dump load apparatus, the apparatus is first placed within a vehicle bed. Once the apparatus is in place, material to be dumped can be loaded into the apparatus. Then, the vehicle is driven to a location where the dumping of the materials is desired. Finally, a force is applied to the apparatus such that the apparatus moves across the vehicle bed so that the apparatus tips over a tailgate of the vehicle bed so that the material to be dumped is dumped.