Hi all. Hadn't drove my car for awhile and apparently a sprinkler has gone haywire where I live. My windshiled has crusty hard water stains now and they ain't comin' out. I've tried mothers chrome polish, an old remedy of vinegar and even lime away. Nothing is working, though the vinegar broke it down just a little. I bought something years ago in an auto parts store that was kind of like a rubbing compound for glass and that worked well but I can't find anything like it anymore.... Anybody got any ideas???

Thanks