Hello,
no PET bottles go in, neither crosswise nor lengthwise without removing the trays,
I hope the question has been answered

No - you have to remove an intermediate rack. To be honest, even the normal wine bottles only just fit in. In other words, I can't manage the specified quantity of 41 bottles. I have a South American, which has a slightly larger bottle, so it's a bit tight... I can't fit 5 bottles in the top.

The shelves are freely adjustable. And the advantage over other cabinets is that the shelves are effectively flat, which means that you can either place bottles or store/cool other things between the wooden rails.
Another advantage is that the cabinet can be set to room temperature = red wine (not just fridge temperature).