IPA Dillution

[Carn]

Maybe I should'nt have called it a film, its like a oily residue. When I take to it with a cloth, it just gets moved about, I've used purple spirits, windowleen etc... it just would not come off. Whenever it's cold and the windshield fogs up inside, you can see this marks/patches/smeers clearly.

The other question for IPA is, is it tint safe?

The IPA should work for the oily residue then. As far as the tint goes I would advise you to test a small spot 1st before spraying the entire window