Yes, its actually perfectly legal, if you are indicating your intention to overtake, and you are still within the legally allowed distance from the other car. D

Yes, its actually perfectly legal, if you are indicating your intention to overtake, and you are still within the legally allowed distance from the other car. Doing this will riding in their trunk, not so much legal anymore. Problem is that this is barely known to anyone, even in Germany. So you will be seen as an asshole anyway.