( http://www.TFLcar.com ) The 2013 Ford Shelby GT500 convertible has a supercharged 5.8-liter V8 that makes 650 horsepower. The monster convertible 2013 Ford Mustang Shelby GT500 celebrates the 20th anniversary of Ford's Special Vehicle Team. Ford engineers built the convertible GT500 to be just as sporty as the hardtop. With an astonishing 650 hp, not only is the 2013 Ford Shelby GT500 one of the most powerful V8s on the planet, it's destine to be one of the fastest Mustangs ever. Ford announced that the 2013 Shelby GT500's lap times at Sebring International Raceway are nearly 3½ seconds faster than the outgoing Shelby GT500.  Check out the Mustang's debut at the 2012 Chicago Auto Show.