(With comfort access), after you put the car in park. Then press the "stop" button to turn off the engine. The electronics are still on in the car. You have to press the stop button a second time or lock the car so that the screen shows "BMW" then switches off.

I wonder if leaving it in the state where the electronics are still on is the culprit of the battery drain. Does anyone know if the electronics will turn itself off when the system detects that the key is no longer around?