Originally Posted by willwren
Just be careful wet sanding and polishing on plastic. You can over-do it in some spots. Don't concentrate on the worst spots and less on the not-so-bad. Do it evenly all the way across.
Yeah, especially on headlights. The plastic used for the housings (at least the 2000-2005 I know for certain) have a "UV" protective coating on them to prevent yellowing from sun exposure. If you wet-sand too deep, you compromise that coating and the housing will be ruined.
I think I would start with a bit more agressive compounding product on a random-orbital polisher; Meguiar'* M83, M84, or 3M Perfect-It II Light or Medium Cut Rubbing Compound would be good choices for the job. Also, it almost looked as if part of the "pitting" was actually in the form of paint overspray (can't tell for certain though). You may want to try a claybar to extract any "grit" before moving on to a polishing/sanding procedure.