That’s a good point. A lot of taxis in Germany are owned by individuals (so while it’s still a business, it’s often a one-person business), but I know they have

That’s a good point. A lot of taxis in Germany are owned by individuals (so while it’s still a business, it’s often a one-person business), but I know they have workshops specifically for taxis, that are probably somewhat specialized on Mercedes. And maintenance packages that factor into the price, which Mercedes likely has if only because of their long tradition as a taxi brand, would play a role as well. Otherwise, I would still expect taxi concession owners to go with the most reliable brand, because any maintenance cost still has to be subtracted from your profit.