The German Federal Police (Bundespolizei) is the central police force of the Federal Republic of Germany, normally police forces are run by the individual states. It has a variety of tasks, from counter-terrorism to border protection. The name was introduced in 2005, when the name “Bundesgrenzschutz” was deemed outdated.
At Hahn Airport, sporting a variety of the old green German police livery (similar to the Bavarian police):
Volkswagen transporter in plain green livery, as was the standard for several years:
Volkswagen transporter in green standard German police livery:
Volkswagen transporter in new blue standard German police livery:
Ford Transit transporter in green standard German police livery, note that this image contains a small in-joke … the vehicle is parked in front of a post office, before privatisation the German Federal Post used the “BP” numberplate later re-allocated to the Bundespolizei: