I took the car by this PM to CC German Motors to leave overnight for my appt tomorrow. The nice lady there wouldn't take my car in when she found out I had just bought it and the dealership had sold it to me. She insisted that I take it immediately to the dealership and that they would have to help me.

I was skeptical and had lost all my trust for them when I found out that the car was not really a one owner car as they had stated and the car immediately started moking and the rear muffler fell off.

The service manager was very friendly and took the car in. He said that since this is a problem that they had worked on before and not fixed, that they would take care of it. Adrian my salesman was also friendly and nice, wanting to make everything allright. They are keeping the car tonight and will see if they can find the problem tomorrow.

I had written these people off as sleazeballs and was prepared to never do business there again. It looks like I may have been mistaken about them and that they are eager to make things right and to keep me as arepaet customer.

I will post the results of the diagnosis and repair when I find out the problem. The symptoms again as first noticed:

And these all seem to be after the car warms up...
Black smoke on acceleration
Hesitation or engine may die leaving a light
<10 mpg
very poor acceleration after warming up, can maintain speed at about 2500 rpm
sometimes have to pump the accelerator to get above 5 mph and then finally kicks in
when it does jump above 3000 rpm huge clouds of black smoke
sometimes the transmission will not shift right and I have to get the rpm pretty high...then it tends to jerk when it shifts

After chatting with the head tech at cc German Motors I am also considering the catalytic converter as a possibility.

Hopefully life with my first MB will go smoother in the second and third weeks.