My MX-6's headlights were really yellow and foggy which dimmed the headlights a lot. In fact, it was one of the worst cases of yellowing I had ever seen on an MX-6. I was afraid of using sandpaper on them, so I tried Turtle Wax's Polishing Compound. After about three 1 minute rub-downs on each light, the headlights look brand new and feel as smooth as glass. The rag had yellow marks on it where the yellow fog came off, so I know it came off and didn't just get covered up. Let me know if any of you have any luck with this - It sure is an easy and scrath free way of fixing them.