Sounds like this car may have had the bad balance shaft/idler gear issue causing the chain to jump or break. There was actually a lawsuit on the topic, and I don't know what MB finally offered, but I think they are offering some limited cost sharing for repairs. Google around and ask the dealer.
I think, but can't confirm, that it is interference, so I would check for bent valves by seeing if any stems don't move fully, or possibly use a borescope in the cylinder.

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Prost!