All 4G combox units are deactivated as of 02/2022.
Go buy any used combox that does not look like it was under the ocean (a lot get water damaged). It is best to buy one with the connectors included with the module.
If you do not get the connectors with the combox you can order them at the dealer. Get the black and green connector with the white insert and not the blue one with the black insert. I can't find the part numbers.
Do not get the kufatec adapter. In my experience they connector doesn't seat properly causing issues. The pin in method of install is the superior way to install a combox.
The antenna wires will need to be adapted with a cheap $7 cable:
https://www.ebay.com/itm/383103945523?var=651682258708
If you have the center console USB you will need an extension cable for the combox:
https://www.ebay.com/itm/264664294201
and a most bus loop (OEM one is 61136917541):
https://www.ebay.com/itm/20308037098...3ABFBM8unCoqhi
The install is super easy and I installed a full CIC + combox in the previous owners condo garage immediately after I bought my M3.
1. Remove the trunk floor.
2. Remove the two 10MM nuts holding the bracket to the car.
3. Disconnect all of the electrical connections.
4. Remove the TCU and MULF (if equipped) 4 8MM nuts per module.
5. Install the most terminator to the MULF most lines (if equipped).
6. Plug in the USB extension cable to the black HSD line.
7. Swap over the power, ground and three microphone wires from the TCU connector to the combox connector.
8. MULF equipped cars will need an extension harness pinned in if you want to retain aux. (None MULF cars can code aux back in)
9. Bolt the combox to the bracket with the 4 8mm nuts.
10. Plug in the main combox connector, TCU most lines, black USB extension cable, tan BT antenna with adapter.
11. Bolt the bracket back to the car.
12. Code the car for combox.