https://www.e90post.com/forums/showthread.php?t=1499808
If you have a pro radio or older idrive.
You can play muse files from usb or sd slot don't know
if you can go that route with a phone but it has a2dp,
Also the link first displayed is a switch from the original box.
Towards the end to the thread I posted the link that has both
the sd and usb ports.