We have a 05 Monterey that has the LED third brake light
A couple of the diodes quit working and it looks.... not so good
Anyway, I did a search and found a company that specifically states they have a replacement for our coach and other Beavers
The company is
spoilerlights.com
It appears the thin lights that are used as third brake lights must have been sourced from the lights in spoilers on the rear deck of some sports cars
I will report on how they work and fit