Die Deutsche Autobahn isn't quite as wide open as it was back in the day but still fun in those "unlimited zones".
Just make sure you know how to drive - left lane for passing only. Germans are militant sticklers when it comes to this. If you're "cruising" in the left lane doing 120, a Porsche or Benz will be flashing their high beams kissing your bumper in no time.
At Autobahn speeds, broken white lines become blurred solid white lines. It's quite a rush, no matter what you're driving.