Chrysler let SRT engineering loose on a 2009 Challenger, and the result is improvements all around. Under the Shaker hood lurks an 8.4L all-aluminum V-10 sourced from the Dodge Viper, which produces an earth-shaking 600 hp and 560 lb-ft of torque. Of course, SRT couldn't just make the car go fast and leave it at that. They also added big brakes and Bilstein shocks all around, an adjustable front spoiler and a carbon-fiber hood and decklid. Inside, the SRT10 Concept gets sport seats, carbon-fiber trim, and a big, red engine-start button like the Viper's.