Why would you say such nonsense in a crossfire forum?
Because it's not nonsense.
Fact is the crossfires were designed for the autobahn just like the SLK. Mechanically it is the same car!
They were designed by the british for American roads. Aerodynamically, they're different which matters at 140mph.
As for the back end... that is why there are pop up spoilers just like Audi and Porsche. To help push the rear end down at high speeds.