For instance, at one point we lost volume and on/off control of the audio system, meaning we had to listen to the audio system whether we wanted to or not (thankfully, we could still change radio stations). Because our driver was on a major Los Angeles freeway in rush hour, he couldn't easily pull over and totally concentrate on the problem, though he was convinced it was something he'd caused while playing with iDrive. After about an hour (or about 5 miles in L.A. rush hour time), the central screen briefly went blank, and then came on with the initial message that was displayed every time the 7 Series was started. More puzzled than ever, our driver decided to give the volume knob another try and ? it worked! He then pressed the knob and the sound system shut off. It seems the computer finally recognized the problem and did the equivalent of a reboot to correct it.
On a different day, we tried utilizing the voice command controls and found the system to be completely non-responsive. It would ask us for commands, but no matter how clearly we spoke, it didn't recognize what we were saying. Acting on our earlier experience with the sound system, we shut the car off completely and restarted it. Sure enough, the voice command now worked perfectly.