It's rather common for the older cars that are experiencing clouded headlight lenses to wet sand away much of the "foggy" marks on the lense. On old acuras there used to be a coating on the outside lense which when sanded off left the lense to turn yellowish in the sun.

Does the MINI have any kind of protective layering on the outside that would keep me from cleaning up a foggy set of lenses i have?

 

I don't know if there's a coating, but I suspect there is. Maybe try a less aggressive approach to your problem? Use some plastic polish or even some light paint polishing compound. You may find that will work for you.

 

Go to a plastics store, like TAP Plastics, and get a Micro Mesh kit. It is a kit designed to take scratches out of clear plastic and plex. I use it for model building, and it works like a charm.

 

I've also had fantastic luck with metal polish. I found about about it when flipping through an Eastwood catalog. They sold a headlight polishing kit that consisted of a buffing wheel and "Autosol" metal polish. I already had a tube of Autosol so I gave it a try on my buddies Honda Civic headlights. Awesome! Worked perfectly. I just used a terry cloth rag instead of a buffing wheel.

Worked for me!

 

I have seen people use Flitz ("as seen on TV!") with good results on plastics.

 

I have used 3M Perfect-it for this problem many times...with great results

 

Meguiars Scratch-X has worked great for me on clear plastic.

 

The guy that painted my wife's car, also sanded the taillights, used clear coat, and these things look better than new. They are crystal clear. They were clear altezzas by the way.