I use this Wagan Cool Air Cushion on my recliner at home. Anyone who is disabled or spends a lot of time sitting on a polyester-filled chair, and lives in hot weather, should have this cushion! Sometimes it feels a little bumpy, uncomfortable, but usually it's just fine. And the cooling air jets really help so much. I wish more people would buy this! It would surely be great in a car, even with air conditioning because sometimes it takes a while for the a/c to start working.
This has no coolant inside which I think is very good - just lift the little flap, press the button (two settings, high or low), and cool air comes out on your back and on the seat/upper legs areas.
The great thing is: it has a very convenient stretchy strap which I use to flip the cushion over the back of my chair when I'm not using it. LOVE IT!