Sometimes the M & M takes a week longer to get to the dealers too. So inform your dealer that you will take the car minus the M &M until it arrives. This gives you time to get used to other bits and pieces of the car, so that when you do eventually get your gadget you can concentrate on fathoming out its ins and outs.
By the way one or two of us on these forums have had slight problems because the neck which connects the gadget to the socket has to be really home. I had to jiggle mine about a good bit and experiment with the release button etc. before it really slotted in. Mine tended to stick up a little on the near side (see other thread,possibly in the technical forum area.) I think I may have cured that now but need a run to see if everything is working correctly.