I've driven many miles, err kilometers, on the autobahn and it can be scary at times. The fastest that I've personally driven on Germany's autobahn was just under 200 KPH (124 MPH). That was in a large Renault sedan when my wife and I were driving from Belgium up to Denmark while I was there on business in 1993 for a couple of weeks. We also spent some time in Holland and eventually flew over to England for about another week before finally flying home. The fastest in which I was a passenger was once when one of our European salesman was driving me to the Bonn airport and we were running late. He promised me that I would make my flight, which I did, but he hit 240 KPH (150 MPH) a couple of times getting me there.
The really scary era was right after the Berlin wall came down. There were some horrific accidents for several months, until the people who were coming over from the former Eastern sector learned how to properly drive on the autobahn. The problem was that in East Germany, the national speed limit had been 100 KPH (61 MPH) and besides, most of their cars were grossly under-powered compared to the average car being driven by West Germans. And they had this nasty habit of changing lanes without looking.
But speaking of the scary parts, while on most of the autobahn, cars had no speed limit, large trucks did and so you would often pass long lines of trucks where you could be going close to twice as fast as they were going.