The best thing I've found for stuff like this Griot's Plastic Cleaner. It's just for sensitive surfaces and leaves behind some protection. But don't get fooled. I wouldn't wash those plastic windows with anything else but car soap and copious amount of running water - because they will scratch easily.
If your looking for something just to spray and wipe them down, I'd use the Griot's stuff or ONR 1:16.
Nothing in a bottle that can prevent scratches on soft plastic like this. But there are polishes to remove the scratches. But, none of them will restore to brand new IME. Also, since this is a "soft" surface, DA polishing will likely be out of the question.
I own the Megs plastic cleaner, and IMHO it's not as good as the Griot's stuff or just ONR.