Underground garage syndrome

Hello oldie friends, inspired by a post here in this forum, “Stress with a senator in the underground garage wg. oil loss” I would like to have an explanation about the following behavior: I have been renting garages or underground parking spaces for over 20 years or even a small hall, so that my darlings always have nice dry. The experiences I make here with the neighbors are not always positive, sometimes it is even spoken out aggressively. Oldies already several times “manipulated” or even deliberately damaged (the roof of my beetle Cabrios was cut open by house inhabitants). A special “specialist” poured 5 liters of oil under my beetles. Without witnesses who had observed the act I would have got a big problem. The cars do not lose oil, the condition is topp, they have TÜV or H-marks and are, at least in summer, registered or have season marks. And then again and again idiots and ask when the car gets away and if the car is standing there even longer! Hardly the cars are not on the parking lot for a few days, then the owner calls if I still need the place. He would have a few calls from people who would like the place. If the cars are nicely packed over the winter, I find under the car a garbage dump every time. Furthermore, some underground parking neighbors realize very quickly that the place between my and her parking lot still as an additional I can use the footprint and push a motorcycle in – distance to my car about “one-finger width”. Can someone explain this behavior to me ? What experiences have you already made ? Christmas greetings ARBE