If it hadn't been for the Hertz Corporation, Shelby American might have only tripled its output in 1966. Instead, with two prototypes and another 1,000 units going to the rental car concern, Shelby more than quadrupled the GT-350 sales tally of 1965.

In a spirited marketing move, Hertz already had formed the Hertz Sports Car Club so presumably adult and responsible renters might add a little spice to their business trips or weekend breaks. For $17 a day or $70 per week (in the New York area), plus 17 cents per mile, anyone with a proven ability to locate the steering wheel and all of the pedals could sign his or her name and drive away.

To most Hertz clients, it amounted to borrowing a personal race car. Naturally legend grew from certain truths. More than a few of the rental units ventured toward drag strips and road-racing tracks to become, if not always competitors, prime parts donor cars. Some competed and certainly most were abused on the highway. Years later, general concern about the condition, upkeep, and maintenance of the old rental units caused them to suffer in reputation and value. That suffering screeched to a halt in the late 1970s and early 1980s, and the cars are held today in the same high regard as their private original-owner counterparts.

The performance rental concept had begun with Hertz's program to offer customers Corvettes. So when Shelby American General Manager Peyton Cramer in September 1965, proposed the sale of a limited number of GT-350s, street versions of that year's B/Production champion, Hertz listened. The corporation's next step,' a shock to Shelby American, was to indicate its intent to order 100 models to be called GT-350H (for Hertz) and to incorporate certain minor changes for driver convenience and safety. The news sent Shelby planners scrambling, and during that period Peyton Cramer continued with his correspondence and negotiations.

A prototype car was requested by Hertz on October 26 and, on November 2 the rental company ordered a December delivery of 100 black cars with gold (Bronze Powder) stripes. The cars would be priced at $3,547 f.o.b. St. Louis—a central location—plus $45.45 for a Shelby-installed radio. Shelby American also offered Hertz Corporation a guaranteed depreciation rate which, in the end, amounted to a sort of buy-back program.

On November 9, Hertz requested an automatic transmission version prototype. It was shipped to Hertz headquarters in New York and, by the end of November, the collaboration had ratcheted up another notch: Hertz increased its order to 200 cars.

According to files found in the mid-1980s in Carroll Shelby's storage areas (and related in the 1987 Shelby American World Registry), a series of meetings ensued, during which Hertz and Shelby American planned a joint advertising effort for major print media—automotive and otherwise. Hertz capped the deal by promising, if the $300,000 ad effort received approval, to order another 800 1966 Shelbys. The official order, for a total of 1,000 GT-350s, arrived in late December.

By December 21, Shelby American knew that the first 200 units would be black with gold stripes and that the subsequent 800 units would be built in a variety of Shelby's 1966 color options. What had begun as a longshot sales call evolved into what would become forty-two percent of Shelby American's assembly efforts for 1966. And Shelby GT-350s, unknown to the nation twelve months earlier, suddenly would appear at more than fifty airport rental facilities, Hertz Sports Car Club Centers, coast to coast.