I installed mine about 400 miles ago, and loaded it up with a pair of heavy shackles, a tree saver, and a 20' strap; there's still decent room to spare for other stuff. I didn't bother with the foam because it is a really bad joke . . . like a hooker with a penis level of bad. There was surprisingly little dust inside despite the lack of foam, much less than my storage stuff in the back. While bashing through the Utah desert, I have not noticed any cooling issues, the gauge stays in the middle. I wouldn't expect any cooling issues with a 7-8" air gap between the trunk and the radiator. Concerning the hoped for effect of minimizing hot air entry into the cab, there doesn't appear to be any reduction in that, seems hot air mostly enters through the shifter hole. The trunk appears sturdy, it's holding the cargo without any rattles, and no noticeable wear or cracking.
Yes, it's expensive, but what add-on isn't overpriced for SxSs? This one appears to work, at least, and ensures I always have recovery equipment handy.
View attachment 219291