The picture I sent you is not mine. I took it from the forum.
I do not think I have this module MULF in my car, since it is not pre-wired.
I was trying to show you how BMW OEM is set, since in your first message, you were asking which way is the OEM way.
I have noticed one thing yesterday, while doing something completely different in the trunk. The E90 DSP is located on the left side of the trunk. I took off all the left side trunk liner and did not find the DSP.
From all the search I did, I think now the DSP is in the wall mount of the trunk opposit to the MULF module. If that is correct, this would mean, the Electrical diagram of the E89 is not the same as the one on the E90...