The you may have the issue I found where the connector doesn't connect the earth for the video signal back to the video module. Then you just need to remove the connector bracket from the rear of the module between teh two front seats and solder the connectors to bridge the the two earths together. I am at a loss as to why this was done this way - I checked other X5's in Australia at least and they were all like that ??? Vintage ~2004

cheers,
seedar.

The AV-In video shield is isolated at the video module to prevent earth loops that cause noise and hum.

BMW never imagined that the AV-IN would be connected to a device like an iPod that was fully floating (independent) from the rest of the vehicle.
The available video sources at the time all required power from the car, and thus the video gound was automatically connected to vehicle ground in the video source.
Eg: the BMW Video Cassette Player that plugged into the AV socket and cigarette lighter. This got it's power and ground from the cigarette lighter socket.

What BMW did is simply good design practice in the early 90's (when the system was originally designed)