I can understand the German’s worry about this.
In the UK, until recently, it was seriously verboten to pass on the right (of course, in the UK that means ‘the left’, because we drive arseways to you). The advantanges are that you only have to pay serious attention to one side of the car while driving on a multi-lane highway, because you know that anything to your right (left) will be going slower than you. The middle and outer lanes are officially called the ‘passing’ lanes. The idea is that you drive in the ‘slow’ lane unless you have to overtake.
In practical terms, however, it doesn’t work very well. People tend to hug the middle lane, because they don’t want to get stuck in the slow lane, due to the density of traffic in the middle lane, due to… (repeat from the beginning of this sentence ad infinitum). You therefore get very slow vehicles in the slow lane, a huge clog of traffic in the middle lane, and people breaking the speed limit in the fast lane. As a consequence the cops in the UK have relaxed about it somewhat, and I’ve heard that if the centre lane traffic is going slower than the speed limit, it’s now OK to pass on the ‘inside’.
The rules are similar in Ireland, but they’re never enforced. People therefore have less lane discipline here too, but as a consequence it works quite well - you can duck and dive in and out of traffic to get through.
Bear in mind, also, that a lot of the Autobahns have very liberal speed limits. To fuck with the lane discipline would invite 200kph cars to come up suddenly behind 100kph cars, with at least a bit of panicked braking, if not carnage.