Initially launched in 2005, the two-door M6 was joined one year later by a soft-top. During the two vehicles' model run, the coupe accounted for nearly two-thirds of all sales, with 9087 models produced. With one year less in dealer showrooms, the convertible sold 5065 copies. Like it did with the M5, BMW saw the most deliveries for its M-powered 6 Series in the United States -- nearly half the allotment was purchased by American buyers, with 3528 coupes and 3247 convertible deliveries recorded. Although the 6 Series is due to be replaced early next year as a 2012 model, we know that the forthcoming M6 and M5 won't be powered by a V-10.

When BMW unleashed its massive 5.0-liter V-10, it was one of the first naturally aspirated engines to produce 100 horsepower per liter. The engine features individual throttle butterfly valves for all 10 of its cylinders, helping it pump out a tire-shredding 500 horsepower and 383 pound-feet of torque. With fuel cutoff set for 8250 rpm, to say the engine's noise is unruly is an understatement. The M6 will be remembered as the final application of BMW's roadgoing V-10 engine.

The turbocharged V-8 in its place is no slouch. Found in BMW's other M vehicles, the 4.4-liter twin-turbocharged V-8 makes an even more impressive 555 horsepower and 500 pound-feet of torque under the hoods of the X5 and X6 M sport-utility vehicles. We recently got our first glimpse of a heavily camouflaged 2012 M6 performing test laps on the Nürburgring, but we expect to get a closer look later this month at the 2010 Paris Motor Show, where the new 6 Series is also expected to bow.