I think if you used the Magic Eraser on the tinted windows. That can get it marred even more sadly. On bare glass though it's not a problem as long as you do a first wipe down on the outside of the windows. So you don't get any abrasive grit in ME. Can be that the owner or the previous owner or another detailer used a glass cleaner with ammonia in it. That's something that you easly can get chemical etching on tinted windows.
Maybe if you are a proffessional detailer and use a lot of glass cleaner it can be a high cost. Sonax Glass Cleaner on the inside of the windows is awesome and a little goes a long way. It's clinging on the glass so no run off if spread out when you spray it on the glass. 2 towels the first for cleaning and flip it often or when you see dirt left streaking. Then it's what the dirt the towel is able to be picking up. Then a mf glass towel that is a little thicker to soak up the residue that don't flash off. Very easy to work with and 2 sprays per the side windows is usually enough for me. And I don't clean the glass as often as I should be doing LOL.
Some like to use panel prep wipe product to clean the glass when it's really dirty. I spray this in the towel so it gets a little damp and you can spread out a layer of it and then clean it up with a second towel.
Maybe try out the Wolfstein Zep Cloth that's liked by many that you only use water to clean the glass with.
Wolfstein?s Zap Cloth
SONAX Glass Cleaner, Glass Clear, auto glass cleaner
If you like the Sonax Glass Cleaner and is a detailer you get it for half of the price when you buy the large 10L jug of it. And get it on a great sale and you save some more the small bottles is 500ml so 10L is 20 refills and a bottle gets down to $6 that way.
SONAX Glass Cleaner 5L.
