Guys,
If you search for movie info online you can find it. Car actually was a 1971 Mustang. Car was stripped of all sheet metal to install a roll cage and other safety features. Movie funding issues caused delays and when sheet metal was reinstalled 1973 parts were used to be as current as possible. There are pictures of car in stripped configuration (bizarre) where I saw this a little while back. It may have been WikiPedia site if you want to have a look.
Also, I'm pretty sure wrecked movie car still exists, runs and drives...
I doubt if (50) special Mustangs were made based on this car. I think movie was released in 1974.
429rb