Got mine from ebay.de as a "kit" -
http://stores.ebay.de/BMW-Autohaus-B...QQftidZ2QQtZkm
What I didn't realise was that as the M-Knob included the gaitor, the LHD version doesn't fit the RHD. What can I say? I ordered it before I got the car...
Luckily, with a bit of slicing, the knob comes off the gaitor and fits in place of the stock knob.
Edit: Useful German Words:
Schaltknauf - gear knob
Leder Manschette - Leather Gaitor
Handbremsgriff - Handbrake Grip
Auspuffblende - Exhaust Tip