A serious problem with a loud banging noise- and feels like a flat tire- in shop for the second time- was told it was the 4-matic system this is a $70,000 car. Not fixed yet. I have 4,000 mi. on the car. Mercedes is not what it used to be.I own many cars. I feel the quality of this car is poor. I also feel that Mercedes is not being responsible enough for quality control.
Go back to the old days and build a great car without problems. Have proper parts available when they are needed.