Incident on the highway

The day before yesterday I drove the A61 and observed the following: Tempolimit 130. 2 driving lanes. On the left an ancient polo drives with almost 120. Behind it a (beautiful ) 5er F10. At some point it was too stupid for the 5er that the polo does not disappear. Blinker left- no reaction. Mal light hoop (everything very polite) – no reaction; even fuchts with the hands from the polo. A bit further, the 5er sets to overtake right (respect for so much patience), the polo pulls jerky right ruby r. The 5er changes to the left to overtake, the polo again to the left. So it went back and forth for a minute. I haven’t seen a dummy like the polo driver yet!! Question: There are users here who do this too. I could almost name names. Why the vulture is made like that?? If it’s a matter of keeping the speed limit and safety, why do you organize such a dangerous circus on the highway, which is the real goal again tonic hte?