The 2020 Mustang GT500 hasn't hit showrooms yet, but Hennessey Performance already has a package for it that turns it into a four-figure hypercar in pony car clothing. Bone stock, the GT500 is rated at 760 horsepower — the most powerful Mustang ever sold to the public. Hennessey adds a twin-turbo system that brings the car to 1,200 horsepower and 1,000 lb-ft of torque — squarely in the territory of million-dollar cars by Bugatti and Koenigsegg. The V8 engine is completely rebuilt with strengthened internals and shifts via a heavy-duty dual-clutch seven-speed automatic transmission. All that power requires E85 or 109 octane fuel, but if 1,200 is a little more than you need, 850 and 1,000 horsepower versions are also available.