I don't know why you use such terms like "misterious" or "solve", as if there was a problem to be solved to begin with. They are obviously intentionally made this way, to keep the fps up, since you surely don't need to see such objects if you are not in the parking.
Of course, Zurich being designed in 2007, we used very conservative settings, since back then no PC would be able to display the whole scenery at the same time, if we ever to remade it for P3D4, with no risk of OOM, we would optimize it differently.
In general, whenever you see something different or might look strange in an FSDT scenery, ask yourself: could be they made it to save fps ? Most of the time, this is the reason.
