Apparently the police get involved, and it involves three of them, when a car parks close enough to another car that their bumpers are touching.
This is Munich. One of the safest places in the world, with no doubt one of the most bored police forces in the world. This means that you can't get away with much. In all honesty, I kind of miss knowing that the police aren't going to bust me for (arguably harmless) misdemeanors because they have more important things to worry about (i.e. homicide, burglary). It was a nice, comforting thought that I could do whatever I wanted because I was a (relatively) good citizen, and if I thought a rule was bogus, to hell with it.
As with everything in life, there are trade-offs for safety and security. Note to self: must remember to leave at least a couple centimeters between cars when I execute one of my super-skilled-tight-parallel-parking jobs.