Bad luck! I don't unfortunately have quality advice for you on electrical faults, but they can be vexing. I have heard that a low battery can result in all sorts of gremlins. A while back, I was stuck in traffic with my 528i at night, and suddenly the motor started acting strangely, several idiot lights came on, and the ABS started pulsing. I pulled over, restarted the car, and all seemed ok. A friend mentioned this issue with low battery. Later that year, I had to replace the battery because it had died in the cold, and since then, I've had no gremlins. Recognizing that cause and effect in your case are fairly removed vis-a-vis battery and radio, it might still be something to consider if other bugs turn up. When my gremlins acted up, I figure that the alternator running at idle for an extended period could't keep up with the electrical load and system voltage dropped to the point where stuff started to happen.
2013 535xi, Carbon Black, beige interior, M Sport package, HUD, DDC & ARS
2010 Z4 35i, Crimson Red, beige interior, 6sp manual, Adapative Suspension
2000 528i, Cosmo Black, beige interior, Sport package (retired)