I've gone round and round with this issue. Seems to be what I first thought was old polish left over from the previous owner on the plastic composite headlights. It's not everywhere, just in some spots. I can feel with my fingernail that it is raised higher than the surface of the lens. Ive tried dupont polishing compound, toothpaste, and Meg PLastX. I did not use a machine, all elbow grease. The haze did not budge one bit. I just cannot bring myself to sand a clear plastic lens with whatever grit sandpaper, it just goes against all logic.

 

Well if your not gonna try and sand that off then good luck.

 

i found that progressive wet sanding... from like 320 grit up through 2000 grit, then using a plastic polish, then putting on a light clear coat and repeating the process works fairly well

 

are you sure you wanna start with a 320? i've never started that low,seems to me that a 320 would leave some pretty deep scratches in there. i always start at 800-1000-1500-2000-2500-3000. that's several steps though. if you don't have all of those grits already you could start at 800/1000 then skip to 1500/2000 then go to 2500/3000. then you're only buying 3 packs of sandpaper.

then after you sand use either some metal polish or plastx with a machine and they should come out crystal clear...minus the pits,etc. that you can't get out by sanding

 

Sanding will hot hurt the lense. Just progressively move to a higher grit paper and polish when done (like stated above). Otherwise, buy some new lenses because you aren't going to get it off.

 

i know wetsanding won't hurt the lense, but 320 sounds a little rough to me. if someone is willing to take something that harshto their lense, then by all means go for it. but i personally have never used anything that low on plastic. 400 would be the bare minimum i would use, but would rather start with a 600 or 800.

just let the sandpaper soak in some soapy water for about 10 min. and it'll be easier to use. and obviously, it would be easier if you take the headlight out of the car.