Quote Originally Posted by vt_maverick View Post
I think what happens is that the factory UV coating reduces over time, and this process is exacerbated when you sand them back to clear. Sanding makes them clear but likely takes off all the UV coating, which is probably why the headlights return to their previous haze/craze more quickly than the first time.

This is why protectors are so critical. I'm eager to get my headlights fixed and covered with Stongard, hopefully that will take care of the issue permanently.
Huh, I'm confused??? Once the factory UV coating is gone; then it's gone for good. Putting the Stonegard covers on is not going to prevent the Sun's UV rays from passing thru the covers and re-yellowing the lenses underneath. The Stonegard protectors only purpose is to protect the lights from flying stones, not UV.