Fascinating to read, sir, and I‘m glad you had such a swell time in Germany then - and you got out of your endeavors unharmed. 😀
And about the Mercedes taxis: in those days, almost all West German taxidrivers used 200 Ds from the firm with the three-pointed star. They were not cheap to buy and slow as molasses (it was said that to measure their acceleration, you needed absolutely no stopwatch, a calendar would more than suffice), but they were almost unbreakable. They ran and ran.
So I wouldn‘t be amazed that, in the long run, using a Merc 200 D as a taxi was cheaper than anything else on the car market.
That was exactly what someone told me when I asked them why taxi drivers would use Mercedes cars!