I've come across a great product for removing the results of years of waterspots and acid rain from auto glass. This may sound like an advertisement but Zaino Z-12 glass polish gets the job done. The tops on my '99 Z-28 had all kinds of spots on them that nothing would remove. I tried amonia, vinegar, and even steel wool. I even took the car to a glass shop and the first thing they said was that nothing could be done except replace the glass. They probably just wanted money. As a last resort, I tried the Z-12 and it got the job done.

I am not going to say the job was easy. I had to use my Porter Cable DA polisher to do most of the work. I only did the edges by hand and even still it took several passes to get the tops looking good. Since it was cloudy outside, you'll have to look closely to see the difference but it is remarkable in person.

Before and after. The top on the left is before and the right is after.


Before


After

 

Zaino makes great products, im not surprosed in the least to see that result from a Zaino product lol. nice work

 

I had a similar issue with the back windows on my '98 Blazer years ago. Here is a picture of what it looked like before my restoration:


Here is what it looked like after:


Believe it or not I used regular Turtle Wax and some 0000 Steel Wool. Well, that and a lot of elbow grease. Picked up the idea from one of the guys on the Blazer forum back in the day when I still owned my Blazer. At first I never thought it was going to work, but as you can see it sure did. Just make sure when you are done to wash the windows with some rubbing alcohol and then a good window cleaner.