For windows or any glass that doesnt have any kind of film on it.. just use windex and a razor blade... if its that tough, i used wd40 to grease it up and wipe/slice it off with a razor blade.... I learned that from my buddies auto glass shop

 

just be careful with applying too much pressure with the razor blades as they can just as easily scratch the glass. Had that happen when my last car was repainted when he used a razorblade to remove overspray on the glass

 

yeah .. razorblades are very tricky to use without scratching your glass ..

 

I usually use DP High Performace Glass Restorer.

 

Nothing better or cheaper than warm water and white vinager. I had tiny water spots all over my windows and after I was done, crystal clear. Wipe and dry with MF towels and done.

 

i know your not supposed to do this but i just use any quick detailer spray. i know it says right on the bottle dont do that buuut it works, very well actually. It also keeps the rain from clinging to the windows. i cleaned my windshield with it once and it started drizzling while i was driving. didnt even need the wipers cause the rain just slid right off haha. but thats just me