BoingBoing dug up this BBC reports on Briton Perry Watkins, who thinks he's built the world's smallest car, complete with a windup key in the back. And as an added bonus, he's built a child, his son Jack, with a mullet almost as big as the car.
Both impressive feats of engineering in their own way, though the car, the Wind Up, may actually go places. It's apparently built from an ATV bike and the hull of a Postman Pat children's ride.
No doubt this would make parking in Chicago easier, but merging onto the Dan Ryan could get kind of interesting.