What can I do to clean/repair a tough stain?
Recently I found this tough stain on the back of my car
glass, and nothing I tried helped. I park in a garage so
it's not from any natural elements. Because it's an
basement garage of a high rise, I'm afraid it might be
something chemical that may have damaged a layer of
the glass?
I used cleaners, white vinegar and water, but it still
didn't work. Does anyone have other advice on how to
clean or repair the stain, without changing the entire
glass?
The picture makes it look like a hard water stain but it
is not, especially since I scrubbed really hard.