I had posted somewhere on the forum a BMW bulletin or a memo, indicating, that if the car is fitted with specific set of options, the main harness can handle some additional options... I am blabbering... lol..

if the car has options set A, B and C - D, E and F can be fitted.
if the car has options set G, H and I - K, L and M can be fitted in addition to A through F...

I need to find my own post... lol...