Robert Redford, and Steve Earle, have owned this 1964 Porsche 904 GTS, formerly the Otto Zipper Precision Motor Cars race entry, one of only 110 Porsche 904s made.

 the second 904 GTS delivered to a customer outside of the works program. 

It raced through 1965. Redford bought it in 1966, and kept the car about a decade

https://gardencitychat.com/celebrities/hollywood-stars-in-their-cars-an-inside-look-at-your-favorite-celebrity-cars/kristineemmy/57183.html
https://hypebeast.com/2022/1/1964-porsche-904-gts-bonhams-auction-robert-redford-previously-owned-info
https://robbreport.com/motors/cars/robert-redford-1964-porsche-904-gts-auction-bonhams-1234657780/