Have to agree with Jim. B.. One of my first jobs was working for a Mazda Dealership writing service. You become a punching bag for any reason. One of my best friends father came in yelling at me because the salesman promised him an AC unite that was not installed on new car. On the other hand a nice lady came in complaining the dash had a creeking sound. The Mechnics are paid by 10th of an hour to repair this once if it goes pass that point they hand back the car fixed or not. I had to pull a dummy repair invoice from a rotory engine to give them more paid time still no results . I felt so bad for her, but my hands were tied.
I finally quit and presued my passion auto detailing. Cars don't talk back and many of your customers are happy when they leave.
If I learned one thing being on this forum is get out the manual and read it. If you don't understand it ask some one who does and have him help explain it to you. If you can not do the work your self fine a good Mercedes-Benz Mechanic and treat him respectfully!!!
Bob Geco
1992 300-E