Do a search on the net. There are many sites dedicated to the Bullitt Mustang and if I recall, there was a site last year that clearly identified the original and stunt double Mustangs. I am thinking they even gave the VINs but I could be wrong.
Supposably the original car was crushed and one of the stunt doubles was sold to an employee of Warner Bros. I believe that car has been located. In addition to Budnates webpage here is another.
http://www.themustangsource.com/time...68/68/bullitt/