Has anyone ever driven the Auto Bahn in Germany? What is it like? How fast?
I have. In the places I drove, it was like an American highway or interstate with the exception of not having a speed limit–although I guess that is a significant difference. That meant that there was a big difference between the slower lanes and the faster ones, which made it difficult for me since I was driving a very small and not very powerful car. I kept pulling into the slow lane, then getting stuck behind a truck, then pulling out (when I finally got a chance) then usually ducking back into the slow lane before a Mercedes or BMW driver started tailgating and blinking his/her lights.
As you can tell, I didn’t drive very fast. I got my little rental Opel up to about 120 kph once and took a picture of the speedometer. It got me some respect from my 10 year old nephew until he realised it was kph, not mph. 
From Davenport, Iowa, to Omaha, Nebraska, is about four hours on I 80. From Kaiserslautern, Germany to Munich is likewise about four hours driving. The big difference is that between the 50 mph straight-truck-and-trailer rigs in the right lane and the orange BMW doing one half the speed of sound in the left lane the autobahn trip is four hours of white knuckle terror, while I 80 is only a few moments of terror when you are sandwiched between two 80,000 lb. semis.
Really, it is close to the same except on the Interstates the trucks are much bigger and much faster and there are fewer cops. Look out for the Geheimnis Autobahn Polietzi.
I found that driving at the faster speeds required quite a bit more focus of attention and left me much more tired than just driving along at my typical 80 mph on the US Interstates. I drove many times from Frankfurt to Switzerland and back, and probably averaged well over 100 miles an hour. It’s not a rush, it’s just driving fast. If you want a rush, get a decent car and drive the back roads near Nice, France. That was something.
A really big difference is that, IMO, most Americans drive like inconsiderate jerks. They have no idea about the concept of staying right except to pass, etc. If you do not follow these rules in Germany then you are fairly likely to get a citation. Oh, and agree that there are not as many big, scary trucks. Although there are quite a few more big, scary Mercedes.