Google's technology depends on a series of lasers attached a large, spinning rotor on the car's hood. Cadillac and GM's technology does not: http://www.pcworld.

Google's technology depends on a series of lasers attached a large, spinning rotor on the car's hood. Cadillac and GM's technology does not: http://www.pcworld.com/article/254192/cadillac_self_driving_cars_out_by_2015_.html http://www.pcworld.com/article/254192/cadillac_self_driving_...