We eventually got the Smart Fortwo (two seats), the McLaren F1 (center drive), and the BMW i3 (city-focused). But none of them have the raw, eccentric charm of the DF104.

Renault called it the "Moteur Billancourt soufflé" —a nod to the legendary 4CV engine, but turned sideways and blown cool by air rather than water. Here is why the DF104 never saw production: The seating.

Do you have a favorite "forgotten prototype"? Share this post with a friend who loves weird old cars.

If you squint, it looks like a melted spaceship from a 1970s sci-fi B-movie. But underneath that fiberglass shell lies the DNA of a revolution that almost was. In the late 1960s, Europe was obsessed with the future. The oil crisis hadn’t hit yet, but engineers knew the days of gas-guzzling behemoths were numbered. Renault tasked its design bureau with a bold mission: Build the ultimate city car of the 1970s.

Renault’s marketing department had a meltdown when they saw the layout. The driver sat in the center. Two passengers sat slightly behind and to the sides, like an arrowhead.

When you think of classic Renaults, the mind usually drifts to the boxy charm of the 4, the rally-dominating R5 Turbo, or the quirky elegance of the Avantime. But tucked away in the secret archives of Renault’s historical collection— l’Usine de Flins —lies a car that breaks all the rules.

Meet the .

Yes, the most successful supermini in French history owes its existence to the DF104. When you sit in an original R5, you are sitting in the ghost of a car too strange for its own time. One surviving DF104 prototype resides in the Renault Conservatoire in Flins, France. It is rarely shown to the public. When it does appear, collectors weep. It is the "missing link" between the post-war 4CV and the hot-hatch revolution.

The result? The (the R5 "Le Car" in the US).

But in 1972, Renault pivoted. Instead of building the radical DF104, they took its soul —the lightweight ethos, the flat engine, the utilitarian interior—and watered it down.