Yea… for those especially HOT days… when my car reaches 120degrees inside… I would really love a 5gallon bomb in my backseat… ya know… to cool me down.
Howabout water? In a mist form can lower ambient temprature 10-20 degrees. Get a misty mate and call it a day… unless you like staying cool, BBQing , and blowing up, all in one unit… then go with propane.