Tried some of the remedies suggested like Clay bar, windex, vinegar and a few others over the last few months and just gave up for a while. Went in Advance Auto to kill some time today and found this stuff. Works wonders and actually does what its advertised to do. I used an applicator for a drill just to make it easier but for some spots I couldn't reach a terrycloth and elbow grease worked too.
For those of you that haven't had any luck and want clean glass heres your solution.