Based on the outgoing 5 Series, this sleek grand tourer comes as a two-door coupe or convertible, as well as the four-door Gran Coupe version. Power comes from a 3.0-liter turbocharged six-cylinder or a 4.4-liter V8, mated to either an eight-speed automatic or a seven-speed automated manual in the M6. The V8 delivers ferocious acceleration and an invigorating exhaust note. But the gear selector in the M6 is unintuitive. Handling is much sharper than the 5 Series, making the big coupe more of a driver's car than its progenitor. The M version is even more performance-oriented. It's quick, capable, and enjoyable to drive.