A vehicle body structure includes a rear seat, a forward shelf and an aft shelf. The forward shelf is movable between first and second retention locations and the aft shelf is movable between horizontal and vertical retention locations defined by side wall structures. The second retention location is above the first retention location. In the second retention location the forward shelf is located proximate an upper end of the upright seatback. With the aft shelf in the horizontal retention location and the forward shelf in the first retention location, the forward shelf and the aft shelf are co-planar. With the seatback upright, the aft shelf in the vertical retention location and the forward shelf in the second retention location, the back surface of the seatback, the forward shelf and the aft shelf define an enclosed storage space.