I have Diamond plate on the inside floor and ramp door. You should see how hot that gets on a sunny day. Same as the roof. When I had my trailer built in 2004. I had them insulate the walls and the roof. It does make a big difference.

548 cu. in., Bill Mitchell Aluminum Block, CRT 727 auto trans, Alston Chassis. 8.981et at 149.46 mph. 1.204et - 60 foot, So Far....