I bought a blackberry Bluetooth receiver, plugs into "aux" in armrest, works seamlessly. Auto connects, when I get a call it stops the music and puts the call throughout the stereo. I think it was 30.00 or so.
By the way, I have the iPhone, point being that ANY cell with Bluetooth will work with this, doesn't have to be blackberry.
M3 Ashtray, M3 Windshield Wash Fluid, M3 Seatbelt buckle...have I impressed you yet.....and all these modds are from the 2017 model M3....