Tonight I have the opportunity to probe the GV with an $8000 thermal imaging camera, wished it was colder outside to get better results. So far as I expected the front firewall area is really poorly protected and could fairly easily and cheaply upgraded on the GV (50 bucks and a day's effort) as there have been many complaints about the cockpit/dash A/C unit. Hope I can post images tomorrow. I posted this while waiting for outside temps to drop.
No reason you cant add some foam board on the back side .
Just by going out at nite and shining in from the front AND then shining out from inside the dash I found quite a few holes by spotting the light.
Cockpit was a lot warmer on the way down this fall.
Exactly as there is not much in they way. entire engine, radiator and air filter bay we're other obvious weak points. Floor is another weak point if you rip out the foam pad and carpeting and go with alternate flooring materials. Internal images looking out only exposed the unisulated rounded roof coves inside of cabinets for the most part, so not much to be gained there as long as the cabinet doors are closed.
pics as promised