You talking about the 3rd brake light? That's a common problem, I was just going to buy a new one and tint it but my dad took a Dremel with a sand paper attachment and lightly sanded it and then polished it. Came out almost good as new..... And then I tinted it so you can't even tell.
Wet sanding should work well also.
Faster than a speeding...............
2001 Bullitt being prepped for track duty
Corners > Straight line
HID end all thread