I am with Cedes on this one.
Just changed the oil at 6K. I am sure the additives are more than adequate for the dealer
recommended change interval, but I do not trust that the filter adequately removes all the abrasive particles that accumulate in the oil over time. ( (combustion blow-by, all that stuff that makes the oil darken over time) The filter and the oil costs $40 total , and I am certain it does not hurt. Plus I did it just to see how hard it is, now I know it is an option.
The filter is behind the engine on the left. You need a 27mm socket wrench w a long extension piece to get at it. I used a vacuum oil extractor to avoid dealing with removing the belly panel and having to buy a new crush washer. The filter is an MB dealer item, right now. When the filter housing cap comes off, it brings the long plastic centerpiece with it, it is clipped to the housing cap , the actual filter can be just pulled off the center piece.