ive use the griots garage glass claybar. thing works wonders on any stains on glass

 

ive always used a 50/50 mixture of Distilled Water and White Vinegar, spray on, dont let soak too long, and scrub with a clean cotton towel.

 

WINK. Its a hard water remover. You can get it from WalMart in the home cleaning department. Comes in a small brown bottle.. hardly has any smell. Pour the wink onto a terry cloth rag because of the coarseness of it and rub vigorously. Its the only thing I use and it gets out the tough tough stuff. Clean with windex when done. Works great.

 

you have a porter cable or a dual action polisher? polish it. it will work.

 

Just go buy a windshield repair shop and buy this stuff called Safelite Glass Cleaner. Its a foam cleaner that does the trick on my car.