A Bill-of-Sale was mentioned up above. In the early 90s I built a replica Cobra. In California I knew registering it was gonna be tricky, and making it look like a 1965 vehicle was gonna be near impossible. A 60s car would never need to go through our oppressive smog system....ever....so this would have been highly desirable.
Anyway, after searching around I found a technique that worked back then. I sold the car (on paper) to some firm in Geogia with a Bill-of-Sale. Turns out in the 60s and before Geogia did not use what we call pink slips here. So the Geogia firm then sold it back to me for $300 more (their fee), and they described it as a 1965 Cobra. I took the BOS from Georgia to my California DMV and attempted to get a pink slip. They looked at me like I was crazy cause all I had was the BOS. I explained this is proper for a car from Georgia. The lady disappeared for a while, I saw her looking through a very think manual. She then came back kind of laughing, and saying how surprised she was that I was right. A few weeks later a California pink slip showed up for a 1965 Ford Cobra.
I wonder if this still works, AND, if something like this could work on the vehicle discussed here.....even though it's a 2004? Maybe turn it into a 60s GT40.....lol.