hey.. as far as the circulation goes... do what I did... I ran a hose from underneath one side of the car, up to the opening that is located in the quarterpanel of the trunk (one on each side.. has a vent on it...)
I just ported forced air (from moving) into there, by facing the hose "forward", and then routed the OTHER hose from the vent(passenger side) to outside the car, facing backwards.... created a "cyclone" of air in my trunk..
Of course, this option doesn't help you if you are sitting still, say, at a car show.. so.. I then cut the intake tube in half, and bought two small 12v fans, and mounted the cut tube to either side of the fans. now.. if I am still, I switch on my fans, and THEY force the air in..
GREAT results.. sometimes I wish I were in my trunk, driving, as it is actually cooler in there, alot of the time..
Ray