Lots of good advice on this site, hoping someone can help me. I have a poorly applied coat of Rain X on my Windshield (2013 STX 4x4) and I cannot get it off. I applied the Rain X and didn't really have enough. It left swirl type "markings" from top to bottom that is only visible when wet or with the defroster on. I have tried Barkeepers Friend, those white sponge/scrubbers, Windex and regular washing and CANNOT get it off! Was Wondering if I should Clay Bar?? I don't know if this would work or if I am wasting my time. It is so bad that if I cannot get it solved I am probably going to replace the windshield. Anyone have any advice ???