Zooks527 wrote up an excellent installation guide called
Installing TechnicPnP Active Sound removal harness at
https://www.2addicts.com/forums/show....php?t=1202389
Having done this yesterday on my 2021 M240i Convertible I noticed a few things that took some extra time that I hadn't seen before so I decided to take a few pictures for those with a similar setup.
1. For those that have a rear seat fold down (like I did), it is two T-20 screws holding that in place. That wire will just hang down when you remove the panel. I thought I could remove the trim panel with it attached but you cannot.