Fuel Filter On 06 E350
In the W210, predecessor to your W211, the fuel filter is behind a panel on the underside of the car just inboard from the left rear jacking pad. It's about 8" x 10" and held in place by 3 fasteners. It may have been moved but it doesn't cost much to check.

You might have better luck getting an answer if you post your technical questions in the W211 forum. This forum doesn't get much traffic.



