It wouldn't be the chemicals (or lack of) I'd worry about, it would be the 2 month old sponge that just finished a filthy 4x4's wheels. On a similar note, washing my windscreen at a servo with most likely someone's mud squeegee left me with about a million micro scratches. Didn't feel any abrasion at the time, but when the afternoon sun hit it, I was not happy. It's bad enough for a replacement I've been told.
On a related note re windscreen cleaning, I wanted to share this tip. If you ever get hard water marks, I've found that (this is going to sound crazy) regular old steel wool with glass cleaner works fantastic at removing them. I tried all sorts of things people recommended, ranging from a lemon cut in half (they say the acid in the lemon breaks down the calcium deposits.......yeah nah, you just look like a fool and it does bugger all) Ordered a product call Bar Keepers Friend from USA, this sort of worked, but not what I was after, and took a ridiculous amount of effort for little result. BKF does work well on you exhaust tips tho!
Finally I found a YT video where the dude used steel wool. Didn't really want to take to my car with steel wool, so i first tried it out on my shower glass. My fears of scratching the glass were soon alleviated, there's literally no way your gonna do that, and after my shower glass came up like brand new with minimal effort, I felt confident to attack the outside glass in on my car.
It comes up like brand new, and you can do a small section, then run your hand down it, then run your hand down a spot you haven't done yet, and actually feel the difference.
Steel wool with glass cleaner, then wipe over with a clean dry microfibre cloth.
