The saga continues...
I've installed the harness, still have a lot of trim removed in the hatch area, and trying to resolve a few issues.
FWIW, I recently installed the headlight switch that has the rear fog lights...the USA builds do not have that switch, but the vehicle itself is capable of using it - I plugged it in, the rear fog lights now can be turned on/off via the new switch...no coding, no additional wiring, just replace the switch.
This brings up a question: The rear taillight assemblies have four wires in their connector. The light has four functions, and I assume it needs ground (unless it gets that by the bolts holding it in). It has: running lights, fog light, turn signal, brake light. How does it get those four functions with four wires in?
Second observation and question: After installation, the only trailer signals I can get to function are turn signals (both left/right and hazards work), and running lights. I did not check rear fog lights, as the 'trailer' I have (actually a bicycle light board - if you're from Europe, you know what that is) doesn't have a foglight in it. So, it must be listening to the CANbus, or it wouldn't operate the running lights or the turn signals, but it is not operating the brake signals. The light board appears to be wired correctly.
Third question: for redundancy and certain emergency situations so you still have trailer brake lights and hazard warnings if the CANbus is off or not functioning (like say the car is off, locked, and you have the hazards on), the harness connects into the vehicle and taps the center brake light line and the right turn signal. The center brake light is supposed to be a black/yellow wire. In the location they indicate in the instructions, I could only find one black/yellow wire, but if it were operating correctly, even if the CANbus wasn't working, it would operate the brake lights. I was wondering if anyone knows any good reason you couldn't tap the brake signal at a taillight verses buried back in the harness elsewhere. If so, which lead is it at the right taillight. Someone had told me blue/black stripe, but there is no wire there with that coloration, or the black/yellow that's supposed to be the center brake light (I sort of would have expected them to all be the same color for the brake function, but hey, I didn't design it).
One of the special features of the Right-Connections harness kit is that it does not require the vehicle to be recoded, as opposed to the OEM kit. Well, it may work fine in the UK market, but unfortunately, it appears that's not true for the USA market vehicles - they would not say it would work, so I can't blame them for any issues....just wondering if anyone else has resolved this.
Now, if BMW made an OEM harness available in the USA, I'd have picked one of those up.