Removing scratches from plastic headlight lens

First of two simultaneous responses --

A. If the damage is not too severe you can polish it out with a cloth buff and buffing compound. Auto stores will have a kit which you can use with a hand held drill.

Second of two simultaneous responses --

A. More likely, Jewelers Rouge will add scratches. Ordinary paste car wax will help fill in the scratches. And because its index of refraction is close to that of the plastic, it does a fairly decent job. Make sure you use *WAX* and not polish! Polish has abrasives in it that generally make things worse. The stuff often used on motorcyclists face shields and other plastics is 'Mirror Glaze [affil links]' made by Meguiars in Irvine, CA. But it will be a lot of work if your lenses are in bad shape.

A. Probably not, most likely it will just make the places you use the rouge will end up smoky rather than clear and shiny. Plastic finishes much different than metals.

A. Most headlight covers have a thin plastic film on top of it . If you use a piece of fine sandpaper you can repair small chips if they are not too deep; afterwards you can polish with a soft polishing wheel with a brown tripoli rouge (polishing/buffing compound) [affil links] and finish with a glaze to remove polishing marks. Be careful not to sand too much, if you go through that plastic film at any place you'll have to sand it completely and polish the whole part to get a uniform finish. Also use a slow speed and light pressure to polish and buff to not overheat the plastic. I have a bit of practice with this, and I get very nice results. Practice on a scrap part first.