Even though my car isn't a GT-R of any kind, so space is less of an issue - my pod used to be noticeably hot after driving...I bought a fibreglass enclosure off a fellow forum member, which he'd had lined with that foil skinned foam stuff on the inside...just a backyard kinda job on the foam stuff.
I drove the car around for a while on a warm day, no constant driving - plenty of traffic lights, then removed the lid of the box and felt the bod immediately after I got home - barely warm to touch,
Just get a fibreglass enclosure for pods, line it with whatever the shit is lining the inside of mine, then run some piping from behind the bar or something to feed fresh air in there.