After performing an led upgrade to a hyundai trajet, I needed to have the plastic assembly of the lamps cleaned. I used plastic polish to get rid of that nasty haze on the headlamps.
You can take a read of my Led upgrade here.
Step 1: Apply the Wax to the Headlamps.
I used one cloth to apply the wax. When dried, I used another to buff the wax off.
Step 2: Clean and Clear Headlamps!
Due to the fact that led headlights generate less heat, these would stay clear for much longer.