This weekend, I installed the Bremman "Wireless CarPlay/Android Auto Retrofit Module - NBT" from ECS Tuning. (my 2017 Clubman JCW is NBT)

Mine has the Harmon Kardon so I moved the optical cable out of the original connector and moved it to the new connector, so it remains plugged in where it was - and I assumed that handles my audio out. Yes, no?
There is also a headphone jack on a very short lead in a bundle including a few video inputs - it's marked "Audio Output". When I power this up and connect to Android Auto, I was able to connect to Spotify and play music, so I am getting music audio.

But then I made a test call to my wife's phone, and I saw my phone connect, but she claimed she could neither hear me nor could I hear her.
I then went back to the car's menu (not Android Auto) and tried to make a Bluetooth call to her, and she said that time she could hear me, but I still had no audio from her.

Any idea what that could be? I'm about to see if I have a headphone extension cable to plug into this "audio out" jack and feed it all the way to my "Aux in" Jack to see if that for some reason is needed for calls, but not other audio.

EDIT: I pulled things back apart to connect an audio cable between "Audio out" and into my car's "Aux In". No change in the phone behavior. I did also go through all the Android Auto "settings" menu, and my car's native menu, confirmed the audio is set to '"aux" in the car (which was also true before I tried this aux cable).

 

The unit seems nice, but the instructions were absolutely terrible - three versions in the manual, CIC, NBT, and EVO - and none of them were clear on which corresponded to this particular unit, as even the NBT diagram didn't resemble what I had on my car or the MMI unit. Also none of them corresponded to a MINI at all. On top of that, they used yellow (looks orange for some reason in the pics) text boxes with white font - I had to break out a magnifying glass. I should also put "diagram" in quotes as many of the connections didn't show really where either "to" or "from" was actually supposed to be connected. Fortunately there is only one way or one place for most of these connectors.


Detail on the DIP switches and that audio out cable...
This is literally all you get:


If anyone knows what these are, I'm currently set to option 2 since I have the 6.5" screen and I can't read Chinese.
But at any rate, I did plug in the cable "aux out" to "aux in" on the car and called my wife - still no luck. She can hear me OK so the factory mic must be working - but I can't hear her. Dead silence.

 

One more thought-
Is the Aux Out / Aux In a 4 position cable? The unit didn't come with a cable to connect the Aux Out to Aux In, so I couldn't tell.
All I have on hand are the stereo cables:


Does anyone know?
You'd think that would be an important detail in the manual.

However, since I have audio for the music, I'm obviously getting audio from the MMI box out.
And I can also listen to the radio, so I am also getting audio from the original unit.
Any help is appreciated - even if you can point me to another manufacturer with better instructions (although I've watched a bunch of other-brand YouTube videos, and there are differences in the cables across all these units, they clearly aren't "all from the same factory" or anything), anything is appreciated.

 

retrofit EVO ID5/6 is the best solution haha. But you may need to replace 8.8 touch CID also.

 

That unfortunately isn't the option that I took... Just to clarify, are you saying that this is a known issue for NBT systems - they can't make phone calls through Android Auto?

I had thought about going that path, but that wouldn't avoid the need for a box like this to get Android Auto. It would have been a LOT of money spent on a "nice to have" without avoiding the cost for what I did buy.
Also I had read there's a need to code the car, to get a(ny) replacement head unit to work with the car. I do have full Bimmercode but that's a whole unknown path of its own, and I'm new to this car to begin with - the goal was to start with the simplest option that presented the fewest risks.

@ECS Tuning are there any support options available? Audio works for music, not for phone calls. AA or BT. Haven't had a chance to try Teams calls yet, that's the other need. Does this resemble any defect scenarios your team has seen?
I did notice that I'm simultaneously connected to two Bluetooth devices on my Pixel 8 (Google's most "vanilla" Android):

• MINI66296 - this is my car,
• Limcet Box_849d - this is the NBT box purchased from ECS

I tried disconnecting from one Bluetooth connection, leaving the other connected, but that did not work either way (and wouldn't have been convenient to do on every drive).

EDIT: Also I did drive today, and I noticed that the levels seem quite low, Spotify or Antennapod. I have the volume set to about 90% to reach a point where I'd call it "louder than conversation". Possibly that's also a clue. This car is new to me so I only have the radio to compare to, which seems to be more like 60% for that same level.