Thanks for the input everyone! Maybe a solution to the ECU issue is to source a used one from germany for such a swap? With as many of these manual tranny E200s in the EU, I'm shocked that MB didn't bother to bring any over to the US, and I'd be surprised if it was a major ordeal for such a transmission upgrade. Not knocking the automatic crowd- but having driven the 190d with 4spd for 5 years, I just can't imagine myself driving this car, or a w210 diesel with an autobox....