Hello George
Here is a simple drawing if you have any question please let me know. I didn`t draw the shelves as you can place them as it suits you. I did not make place for a power panel,starter or tools as all I wanted to carry was the fuel,battery for glow plug,chicken stick,lines and a handle. The door in the box I made out of 1/16 plywood with a 1/4 inch square spruce frame. I made it small to fit the back seat floor area in my 2017 Toyota Corolla. I can only fit one plane in the trunk an another in the back seat when I go flying.
Juan