The film on the inside of the windshield comes from the plastics emitting volatiles which condense on the glass. What works is Autoglym Glass Cleaner. It is a white cream, rub it on the glass, let it dry. Wipe it off with cloth.
Can I use Windex to clean the inside of my windshield?
Yes, you can use Windex on car windows and to clean the inside of your windshield. While some will advise you to skip the Windex with tinted windows, there’s no evidence that Windex with ammonia causes problems.
How do you remove oily film from windshield?
There are a couple of things you can do to remove the oily residue from your windshield.
Clean the stain with liquid dishwashing soap. Use Goo-Gone or acetone (the stuff in nail polish remover). Lightly scrub the oil spot with steel wool and glass cleaner.
