If we are talking about styling then the true design leader in the group has been BMW. BMW's styling is expressive of the chaos, dynamism, speed, and disharmony of contemporary global culture; it is exciting, energetic, aggressive, and fascinating.

Audi is very in tune with what is happening at the elite levels of industrial design -- it is less about dynamic styling and more about an idealized expression of order and harmony. I find Audi design to be the most academic of the three ...perhaps the most intelligent.

Mercedes has followed the changing tastes in the market the closest ....they have adapted particularly to emerging trends coming out of the US. Mercedes is the one that seeks to make connections with its historical past through archetypal design elements -- BMW has the kidney grille and Hoffmeister kink ...but these are not used to evoke history like Mercedes does. Mercedes makes subtle references to its iconic models from the past through the use of stylized retro elements.