Fz: M5 E39 with conversion to 2 DIN, loudspeaker on the radio + active subwoofer in the trunk News Radio: Alpine INE-925W There is only sound left on the subwoofer, a reset of the headunit did nothing. I assume that the preamplifiers have given up the mind. I have already controlled the connection. I have mainly disturbed the following: Current steering wheel remote control: Original BMW multifunction device with an adapter box from Connect2 Requirements for new device: Navigation ben Do you have a tip? Thanks in advance Edit: Almost forgotten, the device should be as short as possible. The E39 is not a 2DIN car, it was converted by an idiot to 2 Din. There is only very little space in the back. A rear retrofit on BMW technology is hardly possible.