"I will admit that I drained the tank and removed the fuel "sock"
from underneath my 300SD and then cleaned the tank " in car" as soon as I took posession of my '84 300SD"

If you have access to compressed air... and take all three connections to the tank loose ( and cap the ones leading to the rest of the car ( two tubes on the drivers side, one on passender side) and take out the fuel sensor tube from inside the car and the fuel screen underneath..... I really see no problem in power washing and drying it in the car....
I just did mine out on the ground... but you have three access holes which are pretty big... and at different sides of the tank..... so with normal drying care you can save yourself a lot of work not pulling it out of the car.

For some reason my next two pictures are too large to post without reducing in size... don't know why since they were made one right after another... will post when I can...

In this picture the crud around the hole is from the gasket sealer for the large cushion gasket which seals the hole in the trunk from outside influence...

Attached Thumbnails