I don't drive my truck through the winter anymore so it is not a big problem for me right now but, I remember the windows used to fog up pretty bad. Newer vehicles seem to be able to avoid the problem better than the older ones do. I have noticed that one of the things the newer trucks have is screen under the slots at the base of the windshield where the heater pulls in its air. When that area gets full of snow the heater blower pulls in snow and blows it on the windshield with the defroster air. This causes the windshield to frost up. I have thought about pulling the panel (can't recall the proper name for it) and putting screen of some sort on the underside of it to keep the snow from falling into it.
So the question is whether anyone else has considered this or acutally done it and if so how and did it help?