Our 2002 A6 had an aftermarket stereo in it when we purchased it - I pulled it out and replaced it with an OEM Symphony CD/Cassette and it works perfectly.... except that it has the ability to be always on regardless of whether the car is running or even if the key is in the ignition.

I took it to a local mobile audio shop and they said that the radio gets its OK to be on from the car from some sort of data signal and that may be bad. I can't remember the term he used for this... does anyone have any input on that?

Another issue with the car is that the dome lights don't come on when the drivers door is opened. Is there some sort of "door open indicator/plunger" type of thing that I should look to replace? What is it called? Could these two issues be related?

 

Door latch has a micro switch that tells the central lock/ comfort module door is open or close. Does the dome light come on when the other doors are open? If that's the case you need to replace the driver door latch assembly.

 

Yes the dome light comes on when the other doors are open

 

Most likely driver's door latch assembly needs to be replace because the Mirco switch is build in to the latch assembly