I have more trouble with fogged up windshields on the inside during heavy rains. Do they make wipers for the inside?

Carl,Rain-X also make an Anti-Fog treatment for inside of the glass,I can't say if it works though but based on their external treatment it might be worth a try.
Also try opening the cowl just a touch and a vent glass or two to purge the humid air a bit quicker.
They are supposed to be "the cab that breathes" after all.
