He is credited for having co-designed the first prototype of the Ford Mustang known as Ford Mustang I with Philip T. Clark. He joined Ford Motor Company"s Apprentice School in Dearborn, Michigan. While working there as a machinist, he was approached by Henry Ford during a plant tour who asked him if he enjoyed his work.
Najjar"s response that he"d "rather be drawing cars" led to an invitation for him to add his talents to Ford"s newly created Design Center.
He continued working as a designer for Ford for over 40 years. He worked with East. T. Gregorie, George Walker, Elwood Engel, Gene Bordinat, and Lee Iacocca.
Foreign many years his work was centered on futuristic show cars whose revolutionary features later appeared in many Ford, Lincoln and Mercury vehicles. The Advanced Styling Studio developed the 1962 Ford Mustang I concept car - so named because of his love for its namesake, the North American P-51 Mustang fighter plane.
His design contributions span decades and include the M4A3 Sherman tank and B-24 bomber in the 1940s, the 1957-1958 Lincoln Continentals, the Mercury XM-800, the LevaCar concept
Najjar also co-designed jointly with fellow Ford Motor Company stylist Bill Schmidt the groundbreaking Lincoln Futura, a futuristic concept car that served as a base for the Batmobile for the 1966 television series Batman, as well as for the first movie adaptation of the Batman comics.