[yreiser]

I went through this recently and can add a few comments:

The gray-red wire coming out of Z44 (mentioned by JKK74) and fuse F57 are only missing in cars that have NO heated steering wheel AND NO vibration actor in the steering wheel. In cars that have the vibration actor (DA /DA Plus / DA Pro), it's always installed. In this case, you don't need another steering column switch cluster either. Both the vibration actor and the heating elements get their power through this same red/gray wire, so if everything is there for one, it's ready for the other too.

The easiest way to be sure everything is there is to simply look if the Fuse F57 (10A) + red/gray wires are installed. This can be done using no tools by simply removing the cover under the glovebox. The pictures are from my LCI - same wire color as preLCI.