Hi, I'm new to the board - just bought 2000 S2000 last week - I'm in Asia. Try Novus, which has 3 plastic polishes. No. 1 is a plastic clean & shine, no.2 is a fine scratch remover and no. 3 is a heavy scratch remover. My plastic rear window was pretty dirty and has the scratch line. It cleaned up a lot with Novus and I'm going to give it another go this weekend. ps this stuff is made in the U.S.
ps loving this car!