The only way in which German cars are at all special is that they make very high horsepower gas burners and nobody else bothers to do that in quantity except for the USA. But that's special as in eating crayons because it's completely ass-backwards in every way.
Japan has been making vehicles of superior quality since the 1990s, which was possible because Germany stopped making vehicles as good as they could in the 1980s and went for absolute cost savings ever since, so it's all the same flimsy plastic shit as everyone else. This is not about valve covers, it's about all the parts which matter. The difference is that the Japanese are actually better engineers. German vehicles depend on parts quality, Japanese ones have more resilient systems. Since Bosch is a bunch of trash like everyone else now, this strategy no longer works and the result is that German cars sprout a new expensive problem every week once they get to be about ten years old. This isn't a problem for rich people who sell cars every couple of years, but it is for everyone else. Incidentally Hitachi hasn't gone to shit like Bosch has so that's another win for Japan.
The very top halo vehicles are somewhat special, although I've seen some reviews of those cars showing parts reuse from lesser models in a lot of them, so they're not as special as you might think. But returning to those plastic valve covers, they don't actually seem to make the cars cheaper, do they? BMW is still charging the same price premium for their marque, just with crappier parts than in the eighties.