Here's a little something I finished up while waiting for progress bars on a different sort of upgrade this week (yes, the vB upgrader has progress bars now).
It isn't quite as elegant as the one that inspired me to try this, but it is compatible with PALS/MOLLE pouches and Staples grid accessories. It also weighs half as much, since the grid is spaced every 2 inches (versus every 1 inch).
Yep, the stock 3rd brake light is fully functional - I have the cover off right now for other reasons.
Speaking of the one that inspired me - does anyone know who's Discovery this is? I was going to give them credit for the idea, but now I can't find the thread...