Hollywood pared down the original Ford Mustang to give the car a stealthy appearance for film, removing the driving lights, running pony grille emblem, Mustang lettering and even the GT badges.
But in fact in was 1968 Ford Mustang Fastback GT 390. By the link you can read little more about movies and TV series using Ford Mustang and its variants.
By the way, the 2008 Mustang Bullitt recalls the movie car – right down to the Dark Highland Green paint and lack of exterior badges, scoops and spoilers. The only visible identification is the word “Bullitt” dropped into a gun-sight graphic in the center of the decklid. A new black-mesh grille on the 2008 Bullitt is devoid of the standard chrome pony and is accented by a satin aluminum strip that represents the chrome grille surround on the 1968 car.