Tree sap I use good old rubbing alcohol. Found nail polish removes paint on some cars, mostly old oxidized cars though. And I always have gallons of alcohol around for putting clear bra's (3m protection) on cars.....and I'm not wasting my good nail polish! Jeez.

Window tint? Take a black garbage bag and cut it open. Press it to the out side of the glass and cut it to shape of window. Jump inside. Spray a heavy mist of water on tint and press plastic so it sticks. Let bake in sun for a while. Should peal off.
If not, try again but use 1/2 h2o & 1/2 rubbing alcohol.
Anything that doesn't peal off? Add some dish soap to mix, spray heavy and scrape with razor. Careful though. Some window will scratch on inside. And lacquer thinner will get off the little itty bitty bits of sticky crap.
Side windows are a b*tch. This method works best on back window but have done it on side windows too.
You can YouTube a method for using a heat gun but I haven't had great results this way.