Politia? In amsterdam they are called polities.
I can see it now.
"In other news the Polities disrupted a protest turned into a mob today by firing tear gas. The polities arrested 27 people." Hilariousness ensues.
There are also stock unmarked Police Logan radars so that's not always true. Also radar detectors are legal, jammers not so. But you're from Germany where they're illegal, so you probably don't own one.
Bottom line is: try and obey every single speed limit and traffic rule, you're more likely to get nicked by the police with a car with foreign plates. Also mind the fact that some cities may have some streets which appear to be two-way, but one way is solely for buses. (I'm talking particularly about a 3km stretch in the center of Cluj-Napoca which, as I see daily, catches out foreigners to the city)