I used to drive 3 to 5 hundred miles per day over a few years. You can learn to spot the problem cars by the ones you see on the side of the roadway out in nowhere. A few German cars, yes, no more than any other cars if you consider the density of car types in a region.
Western US, what I saw most was Ford F-150 trucks, bu hat is a very popular truck, many on the road. Dodge caravan, not so popular and a few of those had been on fire, those are actually Mitsubishi imported by Dodge. Of the German makes, VW I saw most of. Shoe on the other foot, I have see a diesel Mercedes with 1.2 million miles on it.
Friends have cars like Audi and BMW, a few in and out of shops and very expensive fixes.
My last car, an '06 Cadillac DTS, put just short of 300K miles on it, and zero problems or reliability issues, just none.Only in the shop for regular maintenance, sold in excellent used condition.