Try a product called Bio Clean Glass cleaner. I have had very good luck w it. In fact, we liked it so much we used to sell it.
Paste it on and let it work for a few minutes. It has oxalic acid and a very, very fine pumice base. Works great on glass, shower doors, stainless sinks, etc. Does a good job removing hard water stains unless the glass has become etched.
If you have fixed windows, I have a set of tinted rears and maybe side barn doors that are in very good condition.
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV High Top, Custom Walk Through, Lots of stuff added. www.BlingMyRig.com