Story for ya.
I picked up Meguiars PlastX, it apparently removes scratches and polishes plastic, etc. I did a test spot on the window, seemed alright. I did a big spot, buffed it off. and the entire spot was HAZY, real hazy. I nearly cried!
So I got some Meguiars Mirror Glaze #10 - Clear Plastic Polish. It completely removed the haze, hid/removed some scratches, and gave it a REAL nice shine.