Originally Posted by Joliet John

I'll go as low as 600 grit on really bad headlights. I also use a 3" sander. The key is, whatever grit you start with, you have to get everything done with that or you're just going to have to start again. The best way to tell is to have a spray bottle and wet the headlight as you are sanding, so you can see if you got everything.

Then I move up in grit by 200's - 600, 800, 1000 ... from there I go to 1500 then 2000. All you're doing there is getting out the sand scratches from the previous grit.

Then I use a extra cut compound on a wool pad (3" again), buff it clear and smooth, then I use a finishing compound on a black foam pad.