Edmunds inside line has a list.....
The 100 Greatest Cars of All Time
53. 1962 Shelby Cobra 260 and 289: The AC Ace was a boring English sports car with a half-hearted Bristol engine. Carroll Shelby put the small-block Ford V8 in it and created a legend.
52. 1965 Shelby Cobra 427: Shelby designed its own coil-sprung chassis, and fit the massive Ford 427 V8 to create the incredible Cobra 427. It's still one of the quickest cars ever built and it's somehow still in production today.
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Seems a little low on the list, given the continuing enthusiasm....
"Greatness, for the reason of this list, is defined by a vehicle's direct, significant contribution to American automotive culture. That does not mean that a car had to actually have been sold in America, but that its legend changed how other cars are seen in its shadow. Some of the choices here are actually racecars."