The Android unit I mentioned previously just replaces the screen. So you still use the factory LVDS plug, for all the factory functions.
The Android functions are built in to the screen and are accessed by a long press of the iDrive "menu" button or holding your finger on the screen.
The screen comes with a break-in plug & socket wiring harness, for the back of the ccc, the square fakra plug. All you need to do is shift the MOST bus fibre optics from the factory plug to break-in harness plug. The "T" junction wiring from this harness then powers the screen. The screen has a separate plug and socket for the other accessories such as USBs, rev camera, dash cam input, mic etc.
It fairly easy to install, and if you watch a couple of YT vids from hifimax or others, showing how to install first, you'll be fine.
Its a great upgrade.
I've also seen a different upgrade option, a seperate add in box, that gives you just Android Auto or Apple car play to the Factory display. But the pricing seems to similar to the Android screen, which with the additional functions of the screen, I personally can see the benifit of adding just Android Auto.