What early automobile-like machine did Leonardo da Vinci design using coiled springs for power?

Leonardo da Vinci designed a self-propelled cart using coiled springs for power.

The machine appears in drawings from around 1478 to 1480 and is often described as an early automobile or robotic vehicle. Wound springs stored energy and drove the cart's wheels through a system of gears. A programmable steering mechanism, using wooden blocks on a drum, could make the cart follow a set path.

Because Leonardo left no complete construction plan, scholars have reconstructed the cart from his sketches. In 2006, a team in Florence built a working model based on the surviving evidence. It moved without a person pushing it, although it was a demonstration of stored mechanical energy rather than an engine-powered car.

The cart was probably intended for theatrical or ceremonial use. It should not be confused with a modern automobile: it carried no fuel engine and had limited range and control.