Hello Jürgen,
sad to hear that you had such bad luck with the replacement windscreen.

What did MorganPark say as to the crack of the original windscreen? Was this due to a dented frame (as was mine)?
Earlier this month I came across another 4/4 Sport (grey) at the British Car Meeting in Mollis (CH). This one had the same type of crack in the windscreen. ... Unfortunately the owner left with his car before I could leave a note. All I know is that the car has Zürich numberplate.
I talked to my local dealer (Abt Automobile) recently. So far this kind of crack has only been seen on 4/4 Sport cars.

Looks like the manufacturing and fixing of the 4/4S windscreen is different from the other models.