Shelby both backed off the intensity of the GT350 Mustang for ’66 and cranked up production. He built 2380 that year, of which Hertz took 1001 for its Rent-A-Racer program.
Read the full article at Hagerty.com: https://www.hagerty.com/media/magazine-features/25-greatest-mustangs-shelby-gt350-h
I guess I'm confused as to why the author felt that the Hertz variant beat out the other 66 GT350's, since it was essentially a subset of that make/model. I wouldn't contest it's inclusion in this list, but only because it was a 66 Shelby GT350.