I had ceramic windshield tint/film (85%, visually clear) installed this last spring, and it was great for reflecting the summertime heat. However, I noticed this past weekend while driving in some bad weather that there may be a flip side to this coin - it reflects the defrost heat as well? I had originally assumed the ceramic only dealt with the UV/infrared heat from the sun, but I had ice building up despite defroster heat & fan cranked up. Anyone else have this problem, and any solutions other than to remove film?

Make sure to clean the film with an ammonia free glass cleaner. I did not have problems in the past.

Another trick I know would be to wipe your whole windshield with some shaving cream. Sounds weird, but works none the less.
Just apply it to the windshield and remove excess.

I haven't tried it on the same ceramic film though, would be cool to know if it helps.