Worked for me
I had an X-3 back in the day. If I had wireless toggled to "on" on the phone, my Bluetooth would not work and my radio would blank out (no sound). That was a 2007 X-3. I never had that issue with my '09 335 X-Drive sedan nor on my '11 335is. If your phone does have wireless, turn it off. Hope this helps.
2011 Crimson Red 335is