Ok so i havent posted in a long time, but allow me to tell u my situation (mods please move to appropriate are if this is not) I used to be stationed in Hawaii, and the rain water there stains the windows. When i moved back to California i wanted CLEAR windows so i called a few places and found a place that was able to clean my windows. The guy ther used a clay bar and nothing, he then used some chemical and said that if he were to leave it on long enough, it would etch the glass. Fast forward 5 years and a new windshield. Now, only whn its cold and moisture is in the are, i see water stains on the windshield. I've tried clay bar as well as vinegar/ baking soda mix and still nothing. Any ideas what was used on my windshiled orignally becuase i can not stand a dirty windo and these marks hamper my visibility when it rains. The place btw, has gone out of business.