BMW has along history of making big, beautiful sports coupes, and the larger, heavier new 6 Series represents a return to classic luxury two-door styling for the Munich maker. Available now in bahnstorming twin-turbo V8 and, for the first time, turbocharged six-cylinder guises priced from under $180,000, the 6 Series Coupe follows the all-new Convertible launched here in August. Apart from a new-found sense of style, the 650i Coupe delivers all the performance and technology expected at this rarified level, but does it cut the mustard in a top-end coupe segment dominated by accomplished rivals like the Mercedes SL and CL, and Porsche's timeless 911?