On a tangentially related note. Do people really use the deFROST feature to deFOG their windows? If the fog is on the inside, turn on AC (note, this is not equivalent to saying "make your car cold"). The AC will reduce the humidity of the air and get rid of the fog (works quite quickly in my experience).

P.S. I am of course aware that heating the windows will also get rid of the fog, it just seems like an unusual solution to me.