What is the best way to remove water spots, Old water spots, from a car windshield. Thanks folks, my friend is desperate.
If no conventional window cleaners seem to work, then I would suggest rubbing the spots with some toothpaste on a wet cloth. Since the abrasives in toothpaste are very mild, they can remove mineral deposits without damage to the glass.
On glass, there are many things you can try. I’d first leave a vinegar-soaked rag on the spots to see what happens. If that didn’t work, I’d try cleaning with isopropyl alcohol next. Some people claim that Bon Ami in a particular can color (yellow but not gold, if I remember correctly) is safe on glass. I don’t know if a clay bar works on glass, but that’s worth investigating as well.
You could always stop by a detailing shop or an auto glass shop and see if you can get some quick free advice.