I have a similar issue but in my case I lost the lens completely. I believe the culprit was the car wash. I'm attempting to remanufacture the lens using red plexiglass and glue. I won't know the results until I return to Florida (snowbird) in November. You would think they'd sell just a stick-on replacement lens. We can't be the only players in this game. A full brake light replacement is expensive.
gmurf22