To me, the Germans have always been about evolution vs revolution. This can be said about BMW, Mercedes, Audi, and Volkswagen. They evolve their language to suit the current time and, at least to my eyes, are generally timeless designs.
The designs are relevant to their respective generation without dating themselves and looking "old."
I equate them to Vans or All-Stars. Old as can be design-wise, they look old, but they don't look "dated."
Compare this to a Toyota, Lexus, and most domestic cars, where old cars just look old, like a suit with shoulder pads.