ABOUT THIS PHOTO:
The equipment boxes have been painted to match the Sienna's gray interior. Atop them, from top to bottom, are: a green Army laundry bag holding my sleeping bag and pillow, cream anti-sweat rug, non-skid fabric (not visible), and air mattress (just barely visible).
Without the rug, my backside sweats because it is pressed against the non-porous air mattress. Non-skid fabric keeps the rug and me from sliding around on the slippery air mattress. All sleeping gear except for sleeping bag and pillow gets stored in one of the boxes.
ABOUT SYSTEM 5:
My fifth and current system involves sleeping atop a set of plywood boxes having detachable lids. In the Summer of 2010 I built ten plywood boxes of various sizes to hold travel gear. They replace the Rubbermaid totes I had used for years. This system eliminates the need to move things because the boxes stay in place throughout a trip. It also eliminates the plywood-handling nightmare of the previous system---the lids are small enough to be easily handled and stay with the boxes.