I polish and wax all head lights almost every car I detail. While I have not sandblasted, the hand polish does remove the minor imperfections, so I would safely assume that a sandblast would have very good results.
i've used meguires plastic cleaner and polish. I believe it's made for convertible plastic rear windows. It worked ok, not like new, but quite a bit better. I've heard the 2k grit sanding and polishing produces marginal results as well.
I used the meguires product by hand, with a few applications of each product, cleaner and polish. Good enough for me!
There are products made specifically for polishing out scratches and dullness in plastic that work quite well. I used them but don't remember the name. Do a search on the internet, check BMW, if they have something use it. Using the right product can reduce the time and elbow grease involved and make for a beautiful result.
I found it: Novus #1 polish for finish and #2 for removing scratches and dullness, and #3 for heavy scratches.
When we figure it out, we need to print the instructions and place them under the wiper of every parked Dodge Neon we see.. What's up with those cars? They have the most aweful-looking headlight lenses!
Originally posted by ELEVENS When we figure it out, we need to print the instructions and place them under the wiper of every parked Dodge Neon we see.. What's up with those cars? They have the most aweful-looking headlight lenses!
That's funny, you're correct. Isn't it awful. I've even seen some C Class Mercs with the same problem. Tailgating, sun and parking out doors is the culprit.
I found by accident that automotive wax will clear some of the dullness. It is only temporary, so it has to redone once a month. It wont make them crystal clear, but it seems to help a lot. The 200 grit sand paper sounds reasonable, but be very very careful if you do that.
It's not just Neons that do it, but they do seem to be the worst offender. Pretty much most of the Dodge/Plymouth cars I see do it. E36's seem to be pretty bad too, for some reason.
Good luck finding a solution short of replacement.