I just got back from an EXO club run and I noticed that around half the Raptors there are sporting the GJ Motorsports third brake light. I've had one since shortly after getting my Raptor, and it has done exactly what it promised to do, without fail, through many offroad adventures.
I found it a little bit of a PITA to install, as you have to fish your antenna wire through the headliner. I tried doing that without fish tape, and eventually succumbed to buying a roll at my local Home Depot. That did the trick. Unless things have changed, the little doohickeys that you mount for the screws are also a pain: hard to attach, easy to lose and definitely easy to scratch up the paint something fierce.