See also:

Cleaning the steering wheel and gear or selector lever
Thoroughly wipe with a damp cloth or use leather care agents that have been recommended and approved by Mercedes-Benz. ...

The spray nozzles are misaligned
The windshield washer fluid from the spray nozzles no longer hits the center of the windshield. The spray nozzles are misaligned. Have the spray nozzles adjusted at a qualified specialist work ...

Direction of rotation
Tires with a specified direction of rotation have additional benefits, e.g. if there is a risk of hydroplaning. You will only gain these benefits if the correct direction of rotation is mainta ...