I'm a service executive with an MB competitor and one of my responsibilities is retail service delivery. I therefore stay in touch with what goes on with MB, BMW, etc. dealer service operations.
Several dynamics are at work: 1) Summer is the traditional busy period in the auto repair biz, 2) MB's dealers have experienced unprecedented growth in sales volume, which has not yet been matched by comensurate growth in service capacity, that is, available lifts & techs. Lifts and the space they require cost money and qualified techs are hard to find & train. 3), and this may be the biggest problem, MB is experiencing quality problems that are atypical for that brand. In particular, the ML is a real quality dog and it has caused the MB entire service system fits. It doesn't stop there, however, as the SLK, CLK, C & E Class' are not what MB's used to be in terms of quality, and the new S Class apaears to be no better.
My dealer sources claim a significant increase in "things gone wrong" per car sold since '96 and they see no improvement coming from MB. MB's management made a concious decision to cash in on their reuptation to build volume and profits per car. They did this by shortening cycle times and cutting component costs. It remains to be seen how far it can go before the public catches on.
If you want to know how much the automotive quality world has changed, who do you think came out on top in the 1999 JD Power Initial Quality Survey of 1999 models? Was it Acura? BMW? Lexus? Infiniti? Nope, it was JAGUAR! Yes, little Jaguar beat everyone, and when I checked with our dealers who sell Jaguar they confirm that the new Jags are outstanding in terms of quality and reliability. Who'd a thunk it a few years ago?
In my view MB had better wake up or before long they'll become the luxury segments' equivalent of VW in the '70's and '80's, a once-great manufacturer that lost it's way. I look at it this way, for every new owner MB conquests who then becomes disappointed by poor quality, and frustrated by poor dealer service, Jaguar, BMW and Lexus are there to steal the customers from them, just like Toyota and Nissan did to VW in the old days.