On the Mequir's forum they say that mild oxidation on headlight lens material cleans up nicely with just a random orbital buffer and PlastX, while heavier pitting sequires light sanding with 1500 grit, followed by 3000 grit, then PlastX.

http://www.meguiarsonline.com/forums/showthread.php?s=&threadid=8011&highlight=plastic+headlight

BTW, Mequirs sandpapers supposedly have a more uniform average grit than most other brands, so that 1500 grit is an average of grit sizes that are more consistent (less likely to have large scratchy particles).

Some of the most nasty yellowing and oxidation described in a diffeent thread at the Mequirs forum site describe starting with 600 grit.

The PlastX has diminishing abrasives - get emaller as you work them, so they do less scratching then other polishes/scratch removers. I have taken fine scratches out of the wood shifter panel using PlastX.

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E