If I was to do it again, I would insulate the roof of the cab. Hot summers and cold winters. The firewall is where most of the heat comes into the cab. The floor is where most of the noise comes in. With some of the good felt backed, foil covered stuff from a friends Hot Rod project(free, hard to beat that) and some fatigue mat, the cab is much more comfortable. The one thing left to think about, is the firewall hard cover. Hardboard/cardboard or ABS....dollars and time will tell. What is the best? I would guess, it will be a matter of opinion, and preference. Unless some one wants to measure, thermal efficiency, and take sound measurements. Along with moisture and durability tests.
