I have head some issues with audio on my E46 330 Cab, i never figured out what it was, however everything went to normal if i reseted the car. (dissconnect -wire, blackone from the battery for a while) some say 15-20 min, some have to dissconnect for hour or so, to be on the safe side you can do it over night, in the morning when you reconnect everything should be fine.
Keep us posted on the progres

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X5 4,4i-06 Current
330Ci Cab-03 2007-2008
MB E55 AMG-03 2006-2007
Z3 2,8 Roadster-98 2006-2007
X3 2,0d-05 2005-2006
320d-99 1999-2005