Update here too...
Over the past few days the rear electrical systems on the car started behaving very strangely, reverse lights died, PDC came on while moving forward and bootlight flickered on and off. The electric bootlock failed and I had to use the key to open it.
So...last night I had some time and started checking out the wiring.
Turns out that the flexible rubber shroud between the car body and the bootlid seems to be the problem. I removed the cover on the inside of the bootlid to gain access to the wiring, then carefully loosened all the anchors holding the wiring loom in place to gain some free play on the bottom where the loom exits the bootlid.
Next I loosened the rubber shroud and moved it up to expose the wires inside.
Guess what I saw... 4 of the wires broken clean off and 3 with damaged insulation and cores. Its only a miracle that none of them shorted out and blew fuses. I repaired them by soldering each one and then re-insulated it.
Needless to say all the gremlins are now gone.
My conclusion is that the flexible piece has a design fault in that the bend is too acute causing the wires over time to snap off.
See also this thread - http://www.bimmerfest.com/forums/sho...d.php?t=397245