This install was more painless than I expected but not without its gliches.
- Wire color leading to the brake light was backwards. Black was NOT ground as expected and as shown in the Service Manual. First install did not work. Connecting a MultiMeter across the two leads found -11.x volts. Switching the leads made it work.
- Original wires are not long enough to allow comfortable work space.
- Spoiler is tight space.
- Mind the screws and clips. They are easy to lose.
- Verify wiring BEFORE installing. Light bulbs are indifferent to polarity.
- Remove the Bulb and Socket from the housing to allow more work space and so you won't need a helper for testing (you can see the bulb easily from the driver's seat).
- Cut the wiring relatively close to the Bulb and Socket to allow more work space.
Here's the factory wiring that I found. Yours may vary.
Here's my wiring diagram:
With all that in mind follow the vendor's very nice installation instructions. Some photos follow.
The clips that cover the screws pop off with a screwdriver. Gently.
The assembly comes out.
Wires before cutting. Suggest you cut closer to the bulb than I did. Also, remove the bulb holder at this point, the lens assembly is just baggage.
Here's the assembly. I have started wiring but it's wrong.
Wired and putting it all back.
Wired. Note the BackOFF module just visible in the spoiler on the right.
Make sure it does not end up behind the screw clip.