1989 Plymouth Voyager Translucent Headlight Cover

Simoniz liquid polishing compound in the yellow bottle works extremely well in most cases for a few dollars. The more expensive kits do well with a lot more time and effort.

The Lexan composite headlight headlight material is notoriously sensitive to ultraviolet (UV) rays in sunlight and tends to cloud if not UV stabilized. After polishing the lenses to clear again, use a silicon-based car polish with UV blockers on the lenses to retard further clouding.

This video will show you one method: http://www.ehow.com/video_4997499_rid-oxidation-car-lens.html

It struck a chord with me because I'm spending the afternoon polishing out the headlight lenses on my 1998 Yoyager. (I needed a break from working on the dead instrument cluster and potentially dead BCM.) I've used the kits. I've used sandpaper. The Simoniz liquid polishing compound has always been the best compromise between cost, exertion and improvement. I use Racer's Edge aircraft polish available at your local airport FBO for about $20 per bottle as the final step. It's UV protective and Teflon based so it lasts at least six months.