Eureka Aerospace in Pasadena has designed a rooftop device that transmits a microwave radiation to a car, stopping it dead (unless it is pedal-powered).

The above gun is not the actual ray gun mentioned in this article,
 but it could eventually be, and it sure looks awesome!

One beam pulsed in a burst lasting just 50 nanoseconds is enough to disrupt a vehicle’s electrical system. The radiation can overload wires or damage or upset the car’s central microprocessor.

[James Tatoian, CEO of Eureka Aerospace] thinks that with the proper funding, Eureka Aerospace can shrink the device in less than two years to a 50-pound appliance that looks like a plasma television and can disable cars from 600 feet away.

Link

via Boing Boing