The Flatmobile is the world’s smallest car at only 19 inches tall. This is the Guinness record certified car made by Watkins. He has provided a cockpit divider with plenty of switches, an additional jet engine, and several gizmos. This little car was auctioned for only $15,000, which is really surprising. Watkins attempted to make this car three times and finally succeeded, naming it the Flatmobile.