Ron Patrick’s street-legal jet-powered Volkswagen Beetle. The car has two engines - the original production gasoline engine in the front of the car driving the front wheels, and a General Electric Model T58-8F jet engine in the back. The car can be driven legally using the gasoline engine - and when Ron wants to have some fun - he can spin up the jet and get on the afterburner (the jet can be started while the car is in motion). Ron - who has a PhD in Mechanical Engineering from Stanford University - built the car because he wanted the wildest street-legal ride possible. And while he does enjoy the occasional blast on the highway - he has no idea as to its top speed - and probably never will. 
More pics and information here.