I got into my car yesterday and the stereo came on full blast and would only mute, I couldn't turn it down. The sound was also coming through just one speaker (the rear passenger door side). It kept happening even after turning the car off and on a few times, and half an hour later as well. I smelled burning in the car for a moment and got a little worried.

Of course, the dealer couldn't duplicate this and it hasn't happened since. Has anyone had this happen to them and had a fix performed?

and since I drive by the dealer on the way to work, I pulled in and had the service advisor come out to see it. Unfortunately, the techs were not there yet so I left it. Of course when they went to look at it later, it was not doing it any more and there were no codes generated. They had no clue what caused it and had not heard of it happening to anyone else. It only did it the one time and has not happened since. I did not smell anything burning BTW.

2005 A6 3.2

Best I can figure, all this stuff in our cars is computer controlled thus software driven. Your computer crashed, and needed to be reset. The owners manual talks about resetting the MMI system, in the event of failure. Ultimately, my audio anomoly (only low bass, nothing else, on all sources except AM), cleared up, and has not repeated itself.

I recall the days when the most sophisticated electronic component in my car was a Blaupunkt Frankfurt AM/FM radio (pre-digital).

The only thing burning was me! It occurred at a horrible time with guests in the car. It was freezing temperatures that day. The symptoms were exactly the same.

Someone said it was a bad connection in the trunk.

It never returned. I did nothing about it.