A real car IMHO doesn't just go fast around a track or on a straghtaway. Give me some Porche's, BMW's, astin martins, ferrari's and the like on a course like watkins glen. They'll beat anything Shelby designed every time.
When I drive on the road I find that I never drive in large ovals or never ending straight aways. The real challenge is ess turns, shifting, toe to heal, stopping and accelerating.
Shelby's Cobra ate up many a Ferarri, Porsche, etc..., in its day; as did Ford's GT40(after receiving help from Shelby). And, he did so on European turf.
The Europeans have nothing on American autos today. Shelby's Series One, Panoz's Esperante & GTR, Dodge's Viper, and Ford's new GT40 (among others) will hold their own against any European challenger.
Incidently, Jaguar & Aston Martin are both Ford products.