VW simply suffers from the 2000-ish German-Car-Itis disease that plagued all of them: sun-burning the owners with the Check Engine Light.
The problem that VW had that made it worse was the inability for the dealers to fix those problems. Many VW owners drove their cars home with problems still evident. Mercedes has (had, we hope) the same problems, but the dealers were better at sending people home with cars that were "repaired." Sure, the MB would fall apart again next week, but once again, they would have it fixed.
Thanks to the high cost of recalling/repairing an entire production run of cars, makers are "head in the sand" all the time now. Toyota had to be sued by that feisty woman in the US to admit that their long oil change intervals were ruining engines.
The Germans have to work to rebuild their rep. Why bother buying a VW/Audi, BMW or Mercedes when you can get great products with great performance from others and have great build quality? The Germans idea to source all their electronics from a WWI Russian Submarine factory was a bit of goof...