Shelby's Little Red prototype GT500 EXP, the â€œHoly Grailâ€ of lost collector. the car eventually became the model for Ford's popular 1968 Mustang California . â€œLittle Redâ€. LITTLE RED â€“ 1967 SHELBY GT500 EXP PROTOTYPE. be built at Ford's San Jose assembly plant; The first Mustang coupe to receive a 428ci .