It outsold the Honda Accord and the Ford Taurus through the ’90s, making it the best-selling car in the US.

“What were you thinking?” is the age-old riposte, and then a brief pause while the potential customer performs a little mental arithmetic.

“I've got four dollars. Take it or leave it.”

A done deal, and a mother buys a daughter her very first set of wheels. The child is several months shy of two years old. The car looks to be somewhere in its mid-30s.

Before the learner's license, before the first bicycle, before even the very first time playing MarioKart, one homely little plastic machine has given millions their first thrill behind the wheel. Moulded from red and yellow plastic, it is a childhood constant spotted at any preschool or playground across multiple nations.

The design could not be more simple: one door, one steering wheel, four plastic wheels and a horn that honks like a clown's nose. Like the Volkswagen Beetle, this simplicity gives rise to an almost invincible durability. To judge from the delighted shrieks of its new owner, it also drives like a dream.

While paddling his office chair idly over to his desk, designer Jim Mariol was hit by inspiration. At the time, most children’s cars were either ride-on or pedal-powered, but the native of Cincinnati, Ohio, had just experienced a brainwave. He began drawing up plans.

Mariol had a history of automotive design, having won a scholarship to the prestigious University of Cincinnati based on two sketches of cars he submitted as a teenager. His undergraduate degree in industrial design included work as a co-op student with Chrysler, where he styled everything from hubcaps to hood ornaments.

Called up to fight in the Korean War, Mariol would never complete his degree, but took up design as a livelihood after returning from the front. In 1974, his struggling firm landed an account with the Little Tikes toy company.

Tom Murdough, founder of Little Tikes, was a stickler for simplicity. A consummate salesman, he took one look at Mariol's red and black prototype car and figured the company would have a winner on its hands. Production started immediately.

Mariol's approach was straightforward to a fault. By eliminating a complex pedal arrangement in favour of the Fred Flintstone method of foot propulsion, the Cozy Coupe could be offered at a low price with features like an opening door, front wheels on casters, and a moveable steering wheel.

Because it had a proper roof and an enclosed seat, it gave a child the feeling of sitting in a real car, and could be used by very young children – especially if a parent was willing to pitch in with a push or two. The steering wheel might not actually be connected to anything, but the vehicle was easy to control for windmilling little feet.

Sales of the Cozy Coupe were positively explosive. During the early ‘80s, Mariol's firm pulled in over $1m in royalties per year, and in 1991 just over 500,000 Cozy Coupes found their way into driveways and onto backyard decks. It outsold popular family sedans like the Honda Accord and the Ford Taurus through the ’90s, making it the best-selling car in the US (depending on one’s definition of a car), and to date over 10m have cluttered up garages or rumbled down suburban sidewalks.

Not only was it designed in the US, the Cozy Coupe represents one of the few plastic children's toys to be made there. Its Hudson, Ohio, factory employs the same basic process it has since the late ‘70s, moulding the red or yellow body pieces from recyclable Type 4 plastic.

The process is called rotational moulding, and it uses an enormous spinning disc like the world's largest waffle iron. Heated enough to melt a few scoops of powdered plastic, the mould orbits through jets of cold water, allowing the plastic to form a tough hollow shell. Workers then pop out the pieces and de-burr any rough patches.

Though a broken Cozy Coupe might easily be ground up and repurposed as a wastepaper basket or dish rack, most are recycled by the simple act of the hand-me-down. A Coupe might have dozens of owners over the years.

Such was the case with the battered old toy given to Damon Young, a gift from a neighbour who was moving house. It was in still in perfectly acceptable shape, but Young had plans. With a built Nissan 240SX and tuned Mitsubishi Evo under his belt, he set aside his current Toyota-Lexus Frankenstein drift-car build and set to work modifying the little plastic Coupe for his daughter.

The Cozy Coupe remained basically unchanged for decades, but saw facelifts in 1991, 2003, and a fairly radical change in 2008 that included the addition of large eyes and a cartoonish grin. There is now a police car variant, as well as a fire truck and a sporty open convertible.

Parents have further tweaked the original design, painting their kids' Coupes to look like the Batmobile or ECTO-1 from Ghostbusters. Refurbishing the original colour is also fairly popular – the red plastic tends to fade to pink.

Young's version is lowered right to the ground with a chopped roof, fender flares, a “carbon-fibre” rear spoiler and an aftermarket exhaust made out of a Red Bull container. The addition of a handle at the back boosts power from 1 toddler-watt to a full Dadpower. Naturally, with those plastic tires, it does spectacular drifts.

The Coupe is also a direct link to a parent’s wheeled obsession, a vehicle that passes car love directly to the next generation – something that car companies are struggling mightily to accomplish.

The Cozy Coupe doesn't come with a rear-view mirror, but for some of us, it is one. For the toy’s little pilot it affords a view of the winding road ahead, a first few hundred metres to be covered with joy, wonder and wanderlust – and sometimes, with a mean rear wing and custom exhaust out back.