i saw this and am going to ask ESS to activate it / add it on my car..... it seems this is already "coded" into the car and just needs turning on, at least on the e46 m3 anyhow..... wonder if its the same for the z4m?? wouldn't see any reason not.
http://www.youtube.com/watch?v=cQ9zlDwvNeg
http://www.youtube.com/watch?v=cQ9zlDwvNeg