Hi,

My third brake light was giving me intermittent problems and couldnt find anything on how to replace and or even get to this piece so wrote this quick and simple guide.

How to replace the Third Brake Light/ aka the High Mount Lamp on Audi 2003 A4 Cabriolet

This quick tutorial is to show how simple it is to replace the high mount lamp or third brake light once you know how and, of course, aren’t worried about breaking clips or tugging on things you’re not supposed to.

First off, open trunk.



We’re going to want to pry off the grey carpet liner to get to the back of the brake light. And that means first focusing on the hazard plastic. Unscrew the plastic screw and remove the orange plastic. You’ll see two screws holding this black plastic triangle in place.


Once removed, it will look like this:



Look to your left, its time to work on the emergency latch, easily spotted by its glow-in-the-dark handle.


Separate the glow in the dark cover off the handle with a screwdriver or your finger until you see the handle itself.


That screw with the white paint on it is next to go. Unscrew and remove by pulling the handle straight off, toward you.

Next, under the grip is a sneaky little screw covered in carpet fiber:


Here it is removed,


Great, everything is removed and now the only thing holding the liner on are clips. Start gently pulling the liner or trim away from the frame


Eventually you’ll get the entire mold off


On the back, you’ll see the 12 clips that were holding it on-I've circled some on the pic with a highighter


Here’s a close up as you’ll want to make sure all 12 of these get fastened back to the frame when reassembling


Ok, so here’s the trunk lid now.


The third brake light is an entire piece, not just a bulb, and it is the white piece we are looking at.

Just remove the 6 black screws, disconnect the clip on the right and you can pull out and replace in its entirety.

Hope this helps!
Like I said I couldnt find anything detailing this beforehand when I searched.

 

Thank you for this very good write-up and explanation. The trunk of my 2007 a4 cabrio is leaking and I removed the third brake light to trouble shoot the problem. My question is, how do you reinstall the brake light gasket. It is a sponge-like piece of spaghetti that I assume was glued into the brake light lens. I'm not sure how to attach it for reinstallation. I am tempted to just calk the lens rather than use this gasket, but I don't see how it is possible to do a neat job.

Any pointers would be greatly appreciated.