Manual-equipped, 825-horsepower Signature Series Shelby Mustang is how we'd sign our lives away

Ford tuner extraordinaire Shelby American continues to churn out hard-hitting muscle. Hot on the heels of the company's 825-horsepower Super Snake Mustang unveiled in December comes a new Mustang boasting the same power. This one is a tribute to company founder Carroll Shelby and bears his signature. The car is called the Carroll Shelby Signature...