A friend and I did some driving on the Autobahn a couple summers ago. We were in the South part of Germany, near Stuttgart, and outside the city, there pretty much weren't any speed limits, except in one or two spots, or where there was construction. Contrary to what you've heard, it's not always congested in those spots, either. Like in the states, it all depends on where you are and what time of day it is. We had this stupid little rental Volkswagen, and managed to push it up to 160 km/h (about 100 mph) the whole time we were on the highway, and traffic was flying past us in the left lane.

While my buddy was passing someone, we saw headlights way the hell back in the distance. What seemed like a couple of seconds later, after he had moved back over into the right lane, a ferrari blew the fuck by us like we weren't even moving, and we were still going 160. Fun times.