Great timing! If you would have asked 2 days earlier I wouldn't have had an answer.
I've been plagued with the same issue for years on any vehicle with deep tinted glass. You wash the vehicle and chamois it off to prevent water spots but the tinted glass spots up way too quick and then you have to work to get them off.
Just last night I was detailing my coach. I've been using Meguiars products for years with excellent results. However, I've always used Mother's Chrome Polish on my chrome parts. Mother's is like the Bon Ami of polishes - hasn't scratched yet. It's very fine and mild polish and does an excellent job on chrome.
I read the directions on the label (I don't do that too often
) while killing time and I noticed that it said it does a great job on glass and mirrors. Hmmm.... I took one look at this shiny beautiful coach with speckled black windows and I though "let's try it".
I wiped the Mother's Chrome Polish on one window that was really spotted up with a terry cloth towel and within 60 seconds (and hardly any effort) it was clear and sparkly. I wiped it on (it didn't take very much) with a wet towel and then 30 seconds later I took a dry towel and wiped off the haze. No streaks, no spots, no scratches.
I was seriously impressed by how good (and how easy) this stuff worked on glass. Click Here
to view the link to the Mother's website. If you scroll down it's the 6th product on the page. You can find it at almost any place that handles car care products but if you can't, you can always order it direct off the web. I can't believe I've been using this stuff for 30 years on chrome and never tried it on glass before.
See what I mean about reading instructions.