Ever drive a Landcruiser in a snowstorm? The defroster is able to keep a three inch fan-shaped section of your windshield defrosted, dead center, so you have to lean over the stick shift to see out of it. I always kept a bandanna tied around the rearview mirror.In case of inclement weather, you could achieve a semi-transparent glaze of greasy mist across the inside of the windshield by constant wiping.