Diamondite Glasswork Restorer

Brand new cars are prone to "Vinyl Fog", that's where you get a nasty film build-up of all the icky substances used to make the high plastic content of modern cars out-gassing inside the car and while the film is probably on all surfaces you see it on the window.

One tip for getting windows clean is switch to a clean, dry microfiber after making the initial wipe to remove the film and glass cleaner. If you continue using the same cloth your removed the film and glass cleaner with then the chance that you will simply transfer this gunk back onto the window is always a possibility.