The answer: democracy
First, Germans have completely democratized the auto plant by unionizing nearly every single autoworker in the country-under IG Metall, the German autoworkers union. With such a high union membership rate, autoworkers have been able to keep wages high and working conditions satisfactory. But as Horst Mund, the head of the International Department of the German autoworkers union, pointed out, unions hardly ever go on strike in Germany "because there is an elaborate system of conflict resolution that regularly is used to come to the sort of compromise that is acceptable to all parties."
One reason for the more collaborative relationship between CEOs and workers is that, unlike in the United States, unions aren't under attack and there aren't any "right to work for less" zones in Germany to which car manufacturers can flee so they can ignore the voice of organized labor.
Another and perhaps more powerful reason is that there is a constitutional amendment in Germany that forces corporate executives to listen to labor unions. The Works Constitution Act requires every factory to set up a works council that gives representatives of the workers a seat at the table in every decision-making process at factory. That is the democratization of capitalism, expanding the decision-making process to not just the corporate elite but the entirety of the company, from the bottom up.
Thom Hartmann, "If Unions Are Breaking Automakers, Why are BMW and Mercedes so Rich?" Yes! Magazine, Fall 2014: p7