Is there a lot of moisture in the car? This can come from wet clothing, boots, snow on the floor, pets, etc. In some unfortunate cases, it can come from a leaky sunroof or windshield, or an AC evaporator that is not draining properly.For some reasons the rear passenger’s windows are getting really foggy, I’m missing something?
Heat and AC in combination will help remove moisture, but can only do so much. We took the wife's minivan on a road trip last month and has our dog with us. It was hard to keep the back windows defogged because she was excitedly breathing all over them. It was also raining a lot, so we were bringing in a lot of moisture on our clothes after each pit stop.