On another forum a guy had a suv and wanted a something to sit behind the rear seat for storage. He took a sheet of pltwood and cut it to match the area, then cut 2x4's and made a frame for under it and then sat the whole thing in and covered it with matching carpet so he had a raise floor with 3.5" of storage under it then packed all his gear in it. Advantages were it was hidden and didn't really take much cargo space.