Originally Posted by Nathan_h
Yep, that thread is why I asked my question. It looks like the non combox install is just two sets of components: mic and antenna, plus coding. Hard to be simpler, if I am reading that right (which I may not be).
The correct link is on post #19.
Your 2012 E90 does not have any
Telephone pre-wire, so forget about any antenna or mic wiring being there. Either you swap the MULF or simply replace it with the OEM Combox retrofit in the glovebox/under passenger carpet.