I read that some have used lemon pledge. Not only on their windsheilds, but on their paint, as well. I bought a can to check it out, but have not tried it. I simply use hot water and sunwash (hd soap). I use a paper towel or micro fiber cloth.
I use the Novus spray cleaner on my windshield and it works really well. Also have a can of Plexus cleaner. The Novus blue is for normal cleaning and the red bottle is for minor scratch removal.
[8D] I use a wet microfiber bug towel (Walmart) for bug removal,then use Plexus with a microfiber towel.
The Plexus will clean,polish & protect you windshield.
Griots Garage sells a plastic cleaner that is the best thing I have ever used to clean acrilic or lexan.they also sell a plastic polish that helps keep the bug juice from becoming a permanent part of the shield.
Best stuff out there is PLEXUS. Never use Rainex on anything but glass. Never use a paper towel to clean anything but glass - if you use paper towels on your plastic windshield, it'll scratch and leave your windshield unuseable, eventually.
Plexus is great stuff. I tried the Novus and other stuff just to see the difference and nothingis as good as Plexus. Butif I'm traveling, I'll take Novus because it's in a small non-aeresol bottle to clean the window.