Well I don't know the first thing about engines, but I supose it will have coil packs.

As I said, the idling is not really rough - will rather call it uneven. And I dont get any CEL lights or error codes.

Anyone care to comment on my two questions in my first post. This problem is really irritating me. Especially because the Benz mechanics don't know for sure what the problem is, and want to solve it by throwing parts at it.