How to remove the watermark from automobile glass with air conditioner?

There is a watermark on the windshield of the car. You can drive the car to the nearest repair shop nearby. Ask the maintenance master for a little acetone water to wipe, which can completely remove any stains. If you have nail polish for women at home, you can also remove it.

Another possibility is to confirm whether you don't have a back membrane. If there is a film, it may be that the protective film is degummed from the glass, causing visual errors and making you think it is a water mark.