Which Leonardo da Vinci invention is considered an early self-propelled car?

Leonardo's self-propelled cart is considered an early self-propelled car.

Leonardo designed the cart around 1478–1480. Unlike an ordinary wagon, it was powered by coiled springs hidden inside its body. The springs drove the wheels through a system of gears, while steering could be set in advance with blocks or shaped guides. The cart therefore did not need a horse or a person pushing it.

The machine was probably intended for theatrical use rather than transportation. Historians have suggested that it may have carried scenery or created a dramatic effect at court events. Leonardo's surviving drawing does not show every construction detail, so modern reconstructions have helped test how the mechanism worked.

The cart is sometimes called the first automobile, although that label is retrospective. It had no engine, brakes, passenger cabin, or modern steering system. Its importance is that it combined stored mechanical energy, transmission, and programmable steering in a remarkably early vehicle design.