I wonder if this is the same supercharged engine in the SLK230 and previous version of C230. If it is, then I suggest you reconsider before you get a C230. I have know 3 people who have SLK230, and my brother has a C230, and I can tell you that the supercharger setup is a crap. 3 of these 4 cars all had problem with the supercharger, and two of them being the SLK. The SLK's problem was with the fuel mixture. It was something to do with the plenum I think and the problem is that fuel vapor will actually escape out of the engine when you step on the gas. Good thing my friends do smoke. Then there is my brother's car. First, there was this loud metal noise on the right passenger side. The dealer initially thought it was the exhaust, so they tighten the bolts and the noise went away for a while, then it came back again. When we took the car back to the dealer, they eventually said that the supercharger's bearing is bad. This car only had about 30K miles at the time and it had a bearing failure on the supercharger? And I thought my old Eclipse was a junk.
Also, MB service suck. They advertise that they have loaner car, but it turn out to be a rental car. You have to buy additional insurance if you want to drive far (by far they mean like 30 miles), and then you got to fill gas up after you drive. And this was at the largest, and suppose to be most reputable dealer in So. Cal.
Anyway, think twice before you get a MB. We gave MB a chance, and I think that pretty much stop us from ever buying the car again.