This is one of my biggest pet peeves when I tell people how to stop the fogging of your windows on in the interior. Turn the thermostat to full heat and turn the freakin AC on with it. It dehumidifies the air while warming your car up. I've debated with people for hours on end about this and I can't believe everyone doesn't do this trick.
I've never heard of this and I have lived in the northern climates my entire life. I'll have to give that a shot.