I see "USAF" in your user name here, so I'm assuming you're Air Force (me too). With that being said, are you headed to Ramstein or Spang? Either way, you'll love it. I had a blast, the 4 years I spent at Ramstein. TRAVEL TRAVEL TRAVEL every chance you get. It might be one of those "once in a lifetime" opportunities that you'll look back on, and be glad you did.
With the vehicle, you'll get new registration & plates once you get there. Your inprocessing briefings will cover all that crap. You'll have to take a test on basic road rules and those crazy signs (you'll learn the metric system pretty quick, if you haven't already). It's not too hard. You've already got the hook-up from USAA (smart move), so you're one step ahead of the other folks.
One piece of advice regarding Autobahn driving: STAY THE HELL TO THE RIGHT UNLESS YOU'RE PASSING, lest you get mowed over by a Mercedes, Audi, Porsche, or even Volkswagen doing twice your speed. You'll get really cozy using your rearview mirror in no time. Defensive driving & situational awareness takes on a whole new meaning over there. Be safe & have fun!!!