I second getting in touch with Marc Horvat. I had been insuring with "US" agencies ie agencies that cater to Americans in the area for my USAREUR plated car but Marc was able to get me a good quote for German insurance. At least in the Kaiserslautern area, I was unable to find a German agent that would insure a USAREUR plated car but it was really rather easy with Marc. Only downside is that I physically had to bring my insurance paperwork to the USAREUR RMV whereas other US agencies do this electronically, but this is a small inconvenience. This is however only a good option for people who can prove at least a few years of being accident-free so that they can get a good Schadenfreiheitsklasse.