I suppose what got me so upset about the grey water tank was that it appeared to be a simple matter of disconnecting it and pulling it out through the storage bay, but it was too long, even after taking the storage bay door and surrounding frame completely off. However, y’all are correct it’s not a wear item. On mine the previous owner let it freeze and crack, the bottom of the tank was so full of congealed cooking grease (bacon?) that he’d dumped down the drain (what a guy!) that it effectively plugged the crack for quite a while until the grease patch gave out.
Over the years I’ve owned two Mercedes, a 1979 and a 1998. I found both to be generally mechanic friendly when it came to wear items. In several instances you could actually see where the engineers had done things to simplify maintenance. Mercedes is probably the only high-end car I’d buy without hesitation.
Steve