I don't have one of these cars, nor have I worked on one or seen the problem.
However I do work or cars for a living and want to shed some light on the problem.
In the US, all recalls are safty related. Safty related means many prople have been killed, and the famalies have sued and recieved huge settlements. Just because a problem could be safty related doesn't mean the manufacturer will recall it before it happens. In Japan, cars are recalled because of a defect in the manufactur of the car or a part used in the manufacture. SO the MBs were recalled in Japan, and not in the US. MB chose to do as the other car manufacturers do in the country they are sold in.
By the way, I have seen this problem on quite a few Jeep vehicles but found the problem before it caused a problem. The problem is the belt pully is mounted in the rubber, and eventually rips the rubber loose. It takes quite a bit of power to run the alt, A/C, wp, ap, p/s and whatever, so the rubber connection between the crankshaft hub and the belt pully finally gives up.
They can change the numbers from now to eternaty and won't fix the problem until they connect the pully directly to the crankshaft.

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84 500 SEL (307,xxx miles)