I have READ that ammonia removes the window tint. (Google "tint ammonia" or similar.)

I inadvertantly learned that even the little ammonia in Windex starts to eat away at the tint sheet. ("Quick, quick... get that off of there! Hope this rinse with water stops the ammonia cancer...")

I bet the FAQs here has something. :-)

Ah, yes... under Body Glass...

Removing Tint Film:

[Query] How do I remove old window tint film? [Response: Yvan] Grocery-store ammonia is the solvent for tint removal (but use it outside, preferably on a windy day; very bad fumes). Usually tint will come off in big sheets once you get started. Just take your time. For tint installed below the window rubber trim, remove to within one inch above the rubber line then peel the remaining bit from the window using a razor blade and a syringe filled with ammonia that is deposited in the crack. The ammonia will loosen the film (about 15-20 minutes) and you should be able to peel it up from below the rubber. The remaining adhesive comes off easily with ammonia-based window cleaner and a razor blade.