Tirerack shows 225/55 R 16 as the stock size for your car. Mercedes designed the car with that tire size in mind. Going to bigger wheels means more wheel weight and more tire weight. This loads the front end differently. Some custom rims and wheels LOOK real nice but don't drive down the road real good. Sometimes spin balancing ON THE CAR can't get the vibes away. The front lower control arm bushings are under more load with those bigger wheels and tires. Custom alignment settings are sometimes needed. Particularly when raising or lowering a vehicle. Talk to shop that sees a lot of customization and you'll see what is meant. They will tell you sometimes the book settings just don't work. They can make it right because their alignment guys knows alignment, not how to read a computer.
But, if this is the first time you're using those newer tires and/or wheels then you should start there first. Swap around and/or try a 4th or 5th tire/wheel of the same type.