Exterior plastic lenses on a car have it rough out there in all the extreme weather, and over time will encounter surface scratches, get cloudy, hazy, dull and generally tired and old looking. You don't have to give up on them, though, because there is hope in restoring them to their original shine and luster!
Remove the lenses so it will be easier to work with or just wash the lens very thoroughly with a basic cleaner and leave on the car. The advantage of removing them is that they are easier to work with, but this is not required.
There is a factory coating on the plastic for protection. You need to remove this through wet sanding and rubbing compound. Fill up your water container for dipping the sand paper and spray bottle full for spraying the lens. A drop or two of dish soap in the water will keep the water slicker and easier to work with.
Keeping the sandpaper wet and the plastic lens sprayed wet at all times start out with the finest grit sandpaper and work you way towards a heavier grit, only as needed, with your goal being to remove all the surface debris and the factory coating. Finish off with a 1500 to 2000 grit paper for the smoothest surface possible.
Your lens will look worse now than before, but don't worry! Using your rubbing compound, apply small amounts of compound to your applicator and work by hand until you have removed the sanding scratches and the plastic comes back to life, leaving a shine and a smooth surface. Now rinse off any remnants of the compound with clean water, especially rinse out the crevices.
Using your plastic Polish, apply to a haze and then buff back to a shine with your soft clean cloth, and repeat as desired. You should now have a beautiful factory looking finish and shine.
Since you have removed the original factory coating you will want to perform more regular maintenance on the lenses with regular cleaning and polishing.
