Easier than Easy
You are right. The service advisor may have been thinking of an '07. But it's more likely he was thinking $$$.
2 weeks ago I was at the dealership with my '06 CDI and asked about replacing the fuel filter. I was quoted $166.00 before tax.

He said, "it is not an easy procedure" and added, "that's $67 for the filter and $99 installation." (Sign at the service desk reads,
LABOR $115.00 per 1 hour
+++++++++++++++++++++++++++++++++++++++++++++++
Found the filter at autohauz
6460920701
Hengst Fuel Filter; With Water Separator Connection, without Sensor
2005 Mercedes E320 CDI List $53.00 Your price $25.08
also
6460940104
Mann Air Filter
2005 Mercedes E320 CDI List $32.00 Your price $20.23
2118300018
Mann Cabin Air Filter/Pollen Filter; With Activated Charcoal
2005 Mercedes E320 CDI List $49.50 Your price $20.23
Pretty complicated huh? LOL!
Look at it this way, these cars had to be designed to be maintained in 3rd world countries where advanced tooling and complicated repairs cannot be performed. Routine servicing often requires at most a basic set of tools plus the occasional specialty bit ie Torx etc.
I know, I am currently in one of them countries and there are MB's all over the place!
Everyone has encountered games with difficulty levels ranging from "Easy" up through several flavors of "Medium", all the way up to "I Own Your Ass" mode. A small handful, though, include one extra difficulty level.
The Easier Than Easy mode, :baby bottle:where failure is simply not possible. For the most part, such levels are there to allow younger children (ages 3 to 5, mostly), your grandmother, and the hopelessly uncoordinated to play and enjoy the game as well.