The equipment can vary from car to car. There are different levels of sophistication. The possibility that there may be something as simple as a blown fuse in the trunk mounted amplifier is certainly present, there is also the possibility that the sound system has developed some problem that may or may not be from the battery exchange. A scan of the systems within the car done with the proprietary BMW scan tool (called a GT-1) would be my first step in this diagnosis.
Friday, December 3rd, 2010 AT 7:57 PM