You are a legend! Interested though how you managed to ground pin 17 without a relay, usually the only change when selecting reverse if 12volt to the reversing light. but i'll print out the diagrams tomorrow and go from there.

Thanks again :)

In the E46 my USB to IBUS interface has the out (software) for the ground. I believe its built into the interface.

IBUS Interface for BMW cars

On the GNET module and CIS-IBUS its also built into the interface. If you are making your own you will need to probably use a relay as you stated. There was a wire from the GNET interface out the backup light.

Yeah i'll definately go relay route as not looking to install a car PC. Just want to keep it simple. Going to order my NTSC camera today :)

was reading your thread and i just finished my install in a Z4MC and posted everything on the following link Z4 Backup camera - bimmerfest - BMW Forums
Hopefully it helps you out

Curious if the 12VDC attachment to the backup light has any effect on the lighting computer?

I had to use a modified circuit for my LED tail lights on my E46 to "trick" the computer.

i still can use navcoder to eliminate warnings from the reverse light if they ever show up but for now it doesn't give my any fault codes