According to the production #'s posted on the Mach 1 registry web site:
2003 Centennial Coupe - 717
2003 Centennial Vert - 1,323
I have often seen confusion between sales # and production #'s. So they may have made 3,000 of them, as planned, but there is still 960 of them sitting on dealer lots waiting for customers to show up.