The skin is .032 wall outside and inside with a one inch layer of foam sandwiched.
I thought about integrating a fold out tent into the shell, but most of the strength of the structure comes from the roof. The square tube frame is thin stuff. Really light weight, but needs some reinforcing to even put the roof top tent up there.
I am not worried about condensation for a few reasons. The insulated "sandwch" construction, the auto trunk liner carpeting that will be bonded to the entire interior, and the fact that only the dog will sleep back there.
I have a buddy that will be painting the outside to match the truck in the next couple of weeks. After that, the interior can be fininshed. Pics to come...