From the attached OEM tow hitch module installation instructions (sorry dutch version):
- image 082 0052 Z, page10, you can see the brake light is spliced around the passenger trunk hinge from a Black-Yellow (trunk 3rd break light) wire.
- image 082 0053 Z, page 10, Blue-Brown at the passenger side rear light connector is the running (LED) rear lights connection. This Blue-Brown wire (As well as the 2 Can bus connection wires) already spliced at the taped up wire loom behind the module tray location depicted on the top image on page 10. These splices are clearly intended for tow hitch (and PDC) retrofits for the general E82 platform.
EBA AanhangerKoppeling EDoc-456900333.pdf
The TIS schedule for the rearlight connector will be searched and posted later.