Abstract: An apparatus is provided for increasing the useful surface area of a rear seat of an automobile. A first inflatable cell of approximately rectangular block shape fits between the front and rear seats of the automobile. The cell has an upwardly facing top surface for supporting a load at about the level of the seats, and a downwardly facing bottom surface for supporting the cell on a floor of the automobile, or the like. The bottom surface conforms to the shape of the floor and defines a concave portion for accepting a drive shaft hump extending upwardly from the floor. At least one second inflatable cell extends downwardly from the concave portion so that with the first cell and the at least one second cell inflated, the apparatus is caused to fit conformably to the floor and drive shaft hump.