So, I did the following in under an hour. Do it all at your own risk
I did not have to disconnect my battery.
1. Purchase SMD LED Light Bar w/ Red Diodes.
Mine happened to be 2 12" pieces with 9 SMD LED's each.
Let me reiterate: You do not want to purchase cheap/faint LED's and get rear ended by someone because they didn't know you were braking.
2. Unclip 3 retainers towards the rear of the Headliner.
Let the headliner sag/drop down a bit.
3. Remove Rear-Right Passenger Airbag Cover.
You will be snaking your wires, which will require this panel to be removed. Go in the trunk, towards the bottom of the deck shelf: on the right side you will see some exposed sheetmetal and a 3/4" hole. Grab a wire hanger, and slide it through that hole, you will see the other hand conveniently sticking out from behind the Airbag Cover. This is your route.
4. Fasten LED BAR to your board of choice.
The board has to be thick such as cardboard. Fold the board so there are 2 sections: one for the bar, and a bigger section that will slide over the headliner. When the headliner pops back in place, it will hold your DIY contraption quite sturdily. But... DO NOT FASTEN THE HEADLINER JUST YET! Temporarily hold the LED bar in place, where you want it, using tape.
[b]5. Enclose new LED Bar in a SHROUD.[b]
I used the factory shroud, cut in half, and currently being fiberglassed to size
. At the moment, there is tape around the LED Bar to prevent ambient red light from flowing into the cabin.
6. Solder factory plug off of OEM 3rd Brake Light to new LED Bar.
Straight forward.
7. Snake new end using existing route
ie, TAPE IT TO THE HANGER AND PULL FROM THE TRUNK! Then pop Airbag Cover back in place. Pop headliner in place.
8. Plug in and drive safe.
I will post pictures of mine in a few. Hopefully, you can get a headstart now