I notice the model shows a four speed. The majority of these were automatics because a lot of those who rented them couldn't drive a stick Back in the day, the story goes, they were rented on weekends and returned on Monday some without their original motors.
@bob-jackman In 1966, I didn't know any guy who couldn't drive a stick. If you bought anything with an automatic trans back then, you lost all street cred.
In '66, yes, all of us 'cool guys' drove nothing but manual stick-shift trans-equipped cars.
From Hertz own website, a look at the car:
"September 1965 marked the beginning of a landmark business agreement: Hertz’s “Rent-a-Racer” Program partnered with Shelby American to offer the Mustang GT350-H as a rental car to its customers. 1,001 GT350-Hs were added to the Hertz fleet for Hertz Sports Club members to rent.
But how did the program work? If you were a Hertz Sports Club member and over 25 years old, you could rent a 306 horsepower Mustang for $17 per day and 17 cents per mile – a bargain at the time.
Most drivers welcomed this rare opportunity to drive a vehicle that they would never be able to afford to buy. As a result, the Shelby Mustang GT350-H proved very popular among Hertz Sports Club members.
The 1966 Hertz brochure advertised the Mustang GT350-H as a great choice for business and leisure travelers alike. It would appeal to those looking for a new motoring experience and a change of pace.
The Hertz “Rent-a-Racer” Program was a huge success, but eventually reached a point when it was impossible and could no longer continue. The repair expenses became too high and the profit margins too low. The story goes that some customers would take their GT350-H for a weekend of amateur racing and return the vehicle in a ramshackle condition. However, for those who were fortunate enough to experience the magic of renting a racer, the memories live on."
But this, from Hemmings regarding the transmissions. See the second major paragraph of verbage:
https://www.hemmings.com/stories/2019/09/25/history-hertz-rent-a-racer-shelby-gt-h