Thank you DICKBEE for your useful post. I will buy the kit and follow the procedure. This kit is also useful on other cars' headlights too. Everthing is made from plastics these days and plastics do absorb the photons from lights and go through molecular rearrangements. So, it make sense to skim off the first outer layer of the plastics by wet sanding. When I do the procedure, I will post my results.