Well, I'm out of ideas..
Continuing from last week:
Found out after my parade, the transmission shifted rough and very late, the fluid was low, so I filled up.
Today, I went for a testdrive in town, did a few miles, also a lot of reversing action, checked the transmission fluid: A little above full, nice red in color and smelling normal.
Still late and rough shifts at little to medium action on the GO-pedal. Medium to almost full throttle, the shifts are smooth and late..
And then there is the flickering "wait" light, but i covered that, because of reasons..
Still had a good time, just driving around and listening to that 6.2 V8.