Hot Wheels got their start in the 1960s, at a time when many toy cars already existed. However, these existing toy cars were closer to collectible replicas of popular automobiles than fun toys for kids to play with, so Mattel co-founder Elliot Handler decided the company should manufacture its own line of cars. To set them apart from the competition, Handler recruited talent from outside the toy-making world, including Harry Bentley Bradley, a car designer from General Motors, and Jack Ryan, a Yale-educated missile systems engineer. Their goal was to build a miniature car that could move — and more importantly, accelerate in speed — like a real one. To this end, they included wide tires, mag racing wheels, a torsion-bar suspension that provided shock absorbency and wheel bounce, and a low-friction wheel/axle assembly that used violin string and bushings made from Delrin, which had just been invented by DuPont. When Eliot first saw a demo, he exclaimed, “Those are some hot wheels!” and the name stuck. The Hot Wheels Custom Camaro debuted on store shelves in May 1968 and was quickly followed up by 15 additional models: Beatnik Bandit, Custom Barracuda, Custom Corvette, Custom Cougar, Custom Eldorado, Custom Firebird, Custom Fleetside, Custom Mustang, Custom T-Bird, Custom Volkswagen, Deora, Ford J-Car, Hot Heap, Python, and Silhouette. These first edition cars all featured Mattel’s red-lined wheels (which later became a signature element of the toys) and were known as the Sweet 16. Hot Wheels cars were sold alongside flexible, plastic racing tracks that included a now-iconic loop. Over 16 million of the toys were purchased in the first year alone, and in 1991, Mattel manufactured its 1 billionth Hot Wheels toy. Today, Hot Wheels continue to be extremely popular toys and vintage versions are even sought after by collectors.