Sold heavily by the company, the Smart Shift technology HAS NOT BEEN PERFECTED. I purchased 3 M2's in Feb. 2007 with the technology and all are having problems. What's worse, is that the electronics are so complicated the service techs can't fix them. They try to get instructions from Mercedes (maker of Smart Shift) but it appears the troubleshooting is either unclear or "over their heads". Both dealerships in Orlando and Tampa can't fix the problem.
I'm 13 days in the shop with no results on a new vehicle. Don't make the same mistake.