Legend holds that Carroll Shelby trademarked the ‘King of the Road’ name in a hurry after hearing Chevrolet wanted it for a Corvette — securing it for his new 428 Cobra Jet-powered Mustang instead. Shelby built the GT500KR for barely two months in 1968, producing just 1,053 fastbacks and 517 convertibles — 1,570 cars total. Independent road tests of the era clocked it at 5.4 seconds to 60 mph, numbers that placed it among the quickest American cars you could buy.