Kevin at Bolton (Legatha) has kindly written me the following about fitting the vital extra loom (VUL 100310) as follows:
"VUL 100310 I obtained was an exact fit, I simply had to disconnect the big 17 pin BMW connector from the back of my Harmony radio, attach one end of the loom to the car-side connector, and the other to the radio - again these are big BMW 17 pin connectors.
The loom has two other connectors - one goes to the glovebox and connects to the CD changer and one goes to a small 10 pin outlet on the Harmony (it is built into the BMW 17 pin connector) - now here's where it gets interesting, I plugged mine in, the CD changer worked, i.e. it loaded and unloaded and appeared to play CDs, but no sound was forthcoming. More research led me to this post...
https://www.the75andztclub.co.uk/for...nger+blue+clip
So once I had modified the loom's small 10 pin connector (i.e. flipped it 180 degrees) which forms part of the BMW connector to the rear of the radio as advised in that post it was all OK."