Here are some images of Academy/Minicraft's Leonardo da Vinci's Armored Car.
From Leonardo da Vinci's Inventions "
The precursor to the modern tank, Leonardo da Vinci’s armored car invention was capable of moving in any direction and was equipped with a large number of weapons. The most famous of da Vinci’s war machines, the armored car was designed to intimidate and scatter an opposing army.
Da Vinci’s vehicle has a number of light cannons arranged on a circular platform with wheels that allow for 360-degree range. The platform is covered by a large protective cover (much like a turtle’s shell), reinforced with metal plates, which was to be slanted to better deflect enemy fire. There is a sighting turret on top to coordinate the firing of the canons and the steering of the vehicle.
The motion of the machine was to be powered by eight men inside of the tank who would constantly turn cranks to spin the wheels. Leonardo suggested in his notes that the thought of using horses for power crossed his mind, but he dismissed it because he feared the animals would become too unpredictable in the confines of the tank.
Despite its elaborate design, da Vinci’s tank has a major flaw - the powering cranks went in opposite directions. This made forward motion impossible. Scholars suggest such a basic engineering flaw would never have escaped the detail-oriented mind of Leonardo da Vinci, and that he may have inserted the flaw intentionally. A pacifist at heart, da Vinci might have sabotaged his own design to discourage the war machine from every being built.