I lived in Germany for 5 years, in Frankfurt, and I had 2 cars brought over from the states during that period, and converted them to German plates and registration. When you pick up the car from customs, you might have to pay them duty, check that out in advance. Since I was working for Lufthansa, I had a reduced rate in which to transport the cars, otherwise by ship is the cheaper route. If your in the military, you fall under a different set of rules for plates and registration, which basically by-passes the TUV.
The TUV is the german equivalent of the DOT. Here is a link in english: http://www.tuv.com/en/usa/home.jsp. If you plan on converting the car, they will tell you what you need to do when its inspected. Basically you cannot change the car in any way from stock, without it being stated in the registration (Fahrzeugbrief). Any changes need to be approved by them. The speedometer has to state Kilometers per hour, and it is acceptable to have both MPH and KPH on the dial together like some American cars.
When you take your car to the TUV, be prepared for the typical government paperwork, and be patient. You will probably need someone to help you translate if you don't speak German, since the paperwork will be in German. I had to take my cars back numerous times for inspections after modifications of things like the emergency flasher switch (has to be illuminated with the lights on), and the removal of the middle brake light. If your car came with a Cat, make sure you have it on when you go. Their inspections are VERY through, and even things like sheet metal rust is not allowed (repaired is OK).
I lived there from 1988 thru 1993, so things could have changed obviously since then. Oh, and by the way, you can get a set of temporary plates to drive on while you are trying to get your actual plates and registration. If you have any questions, let me know.