blaubenz , I linked to this thread via the home page and only looked quickly at the first post and your post .
the filler for this transmission is indeed on the sump pan . it has a stand pipe rising into the sump .
these transmissions should be filled to overflow then run the engine , top up more , shift through all gears with your foot firmly on the brake of course and the vehicle safe , engage park , continue topping up fluid until a small stream overflows .
the fluid should reach at least 30 C and not more than 50 C .

EDIT . I just read this thread and RRPhil shows photo`s of a different fill point to the one I mentioned .http://www.xoutpost.com/bmw-sav-foru...5-4-4-a-2.html
I am going from memory of info in the Bentley manual .