Sorry Gentlemen, I've been off the grid for a while...
Rolf-Dieter,
Concerning your question on speed vs rpm. My CLA 45 has 7 speeds and 3 modes...Comfort, Sport and Manual. It also has an ECO button that I seldom use. Not sure what your E350 has...6 speeds? To be honest, sometimes, I believe it revs and shifts too low in Comfort. I find myself driving it in Sport mode or Manual. I will check for sure but, I believe it does 75mph @ 2000 in Comfort mode. Sport mode may be 2100 at 75mph.
The other thing I've noticed, as you might expect, it doesn't have the deep throat of a naturally aspirated 360 horsepower car. It has a rally car sound. Not bad just different. All in all the CLA 45 AMG is a great car. I highly recommend it..