I fill-in most of the storage boxes in the 'garage' of my van. They are all open boxes with inter-locking bottoms, except for the top box, which receives a top lid. This Formica-finished top lid has three functions: as a top lid of course, as an extension of the kitchen countertop and as a worktop placed on a imperfect picnic table.
The Desk Seat is a simple cover over the foldup workbench, which hides it from view. A bright red cushion will be added later.