The Chrysler Crossfire shares much of its engineering with the last-generation Mercedes-Benz SLK. It's even built in Germany. You won't see anymore of this, though. DaimlerChrysler has said they don't want to sully the image of Mercedes-Benz by sharing even the bones of Mercedes vehicles with the American side of the family.
Rationally, of course, there's no reason why having Chrysler Group products using Mercedes platforms should harm Mercedes. But a Mercedes buyer might feel less special knowing that some guy in a Dodge is driving around with some of the same parts.