Glass Polish

I bought a new toyota tundra and it had real bad hard water spots that would not clean off. The dealer said to bring it in and they would clean the glass. When I got it back it was amazingly clean. I found out they used pro glass polish, so I ordered some. Took hard water spots off all my Windows. Two quarts lasted me 7 years. Just ordered one for me and one for a friend. My Lexus had spots for years and it cleaned the glass like New.