Emulator. I got mine from Adrian for my e60.
My e70 is coming up right behind it because of idrive controller and CCC issues.
I've looked at just CIC but there is so much stuff to buy just for that I figured I might as well go NBT.

You may need a Fx antenna amp for 2nd antenna lead for better traffic info.
An extended fakra cable for sdars.
And maybe a few more cables.
I haven't started tearing apart yet. So you're ahead of me.