I haven't seen this listed yet. The R56 manual has a picture of the mobility kit, only it's sitting in a tray in the boot. There are a couple of those styrofoam inserts-the one that comes with the car, and a different one. The new styrofoam insert that replaces the one in there is P/N 71 11 6 762 288.

I bought a jack and lug wrench , the new tray, and the mobility kit and it all fits under the cover (and also holds the tow hook, wrench, and screwdriver). Kinda neat. You don't have to have that black bag floating around the boot. The sealant doesn't fit too well in the tray-a bit oversized-but I shoved it in there anyway. I put the manual on top of the pump and it evens it out.

P106 of The Manual shows the mobility kit in the tray.