Actually, you’re wrong…
They used a total of 6 normal 1967 Ford Mustang Fastbacks, 5 were V8 powered which were the stunt vehicles that were beat on and crashed etc. and the 6th was an actual RB26 swapped Fastback that was Rhys Millen’s, which got all the credit. It made 340whp, and ran 13.5 @ 110mph.