Few cars in history have had a greater impact on the U.S. auto industry than the Ford Mustang. 

A half century after its release, the Mustang continues to hold the world record for first-year sales, with 418,812 cars sold. The new documentary A Faster Horse, which recently premiered at the Tribeca Film Festival in New York, follows the team of engineers and designers tasked with reinventing the Mustang in time for its 50th anniversary in 2015.

Directed by David Gelb, whose 2011 award-winning documentary Jiro Dreams of Sushi focused on the 85-year-old sushi master Jiro Ono, A Faster Horse shadows the Mustang's chief program engineer Dave Pericak during a two-year period in which the stakes have almost never been higher for Ford. Having committed to a complete redesign of the crown jewel of its fleet during the heart of the economic crisis, the company has a billion dollars invested in the 2015 Mustang, with thousands of jobs dependent on the success of the new model.

"The pencils are down," Pericak says at the beginning of the film. "It's pure execution phase from here." 

Part of what makes A Faster Horse so compelling is the way it pulls back the curtain on the highly secretive process of a massive corporation putting the finishing touches on a legendary product. Unlike previous iterations, the 2015 Mustang is the first designed to be sold around the world. During the final stretches of Ford's "manufacturing launch phase," engineers obsess over perfecting tiny details, including the sound that's made when the car's doors close.

"Every millimeter of the car is fought over," Pericak says.

A Risky Bet

Adding depth to the documentary is the storied history of the Mustang, which has been sold more than nine million times. In the early 1960s, sensing a demographic shift in the U.S. due to the baby boomer generation, former Ford executive Lee Iacocca spearheaded the development of the Mustang, a new model designed to be fast but also affordable for young Americans.  

Originally named the Cougar, the Mustang was conceived as a fun car built on the principles of simplicity and durability. Coming on the heels of the Ford Edsel, one of the biggest flops in the history of the auto industry, the Mustang was an untested idea that faced intense opposition from Ford executives during its development, a fact that has helped make the car synonymous with courage, innovation and rule-breaking.

Upon its release, the Mustang was so popular that Ford dealers called police to help manage the crowds at dealerships. To this day, the Mustang is the only car to simultaneously be featured on the cover of both Time magazine and Newsweek

Beyond a Brand

The suspense of the film comes from the product's tight time frame. With just months to go before mass production of the car was scheduled to begin in the summer of 2014, Pericak and his team race to get final approval for the more than 2,000 individual parts that comprise the Mustang. Far from being an updated version of the previous model, every part of the 2015 Mustang is completely new, designed and engineered from scratch. When test-driving the car in secret locations, the Mustang has to be cloaked in a black tarp to prevent images of the new design from being leaked.

For Pericak, working on the Mustang is a life-long obsession that the filmmakers portray as much more than a job.

"Everyone gets so emotional about Mustang because everyone is passionate about the car," says Pericak, who joined Ford as a manufacturing engineer in 1994 and even proposed to his wife in a Mustang.

In the winter of 2015, during the final stretches of releasing one of the world's most recognizable cars, what is clear is that everyone involved with Mustang continues to be mindful of the rebellious spirit of Henry Ford. Famously, he stressed the importance of anticipating the needs of consumers by saying: "If I asked the farmers what they wanted, the would have just said a faster horse."