I asked my dealer to check it, the service writer told me they dont, since they dont get paid for it. I almost went thru the roof, after calling MB customer relations and getting some arrogant call center idiot, I asked if there was a problem or not. The resuling answer did not agree or deny, so asked him to deny there is/was a problem and the answer was that I was "putting words in his mouth"
I went to my dealer and asked the service manager this time, they looked at it and concuded they should change it, and did, on the spot while I waited.
MB better get their head on straight, they seem to be following what the US manufacturers did in the sixties. Lexus, and some US mfrs. have learned, and seem to be be cheaper and more reliable mode of transportation. I thought my ML was just unusual in its problems, but it was a leading indicator. (see consumer reports)