This my seem bizarre but I use 0000 steel wool with Sprayway glass cleaner as a lubricant ( just be sure it's 0000). It has ever scratched a variety of glass that I have applied to it. I got the hint from a professional detailer. Try it on one of the corners to be sure but it seemed to help on other cars I had. I have used it on non automotive glass to remove stubborn stains that had developed on the glass. Has anyone else tried this and had scratches?
Dave
Dave