text: Television and movies have developed a theory of these cars. The theory is how the car may look and also, drive. Google has had cars that could drive independently under certain circumstances since 2009. Google cars have driven over half a million miles without a crash. google's modified Toyota Prius uses position-estimating sensors on the left rear wheel, a rotating sensor on the roof, a video camera mounted near the rearview mirror, four automotive radar sensors, a GPS receiver, and a inertial motion sensor.