Ford's Focus, and other Ford models, may soon include a new automated self-parking system. Photo credit: Ford Motor Co.

Automakers have said that true self-driving cars are unlikely to appear on American roads before 2020. There are many obstacles still to be overcome. But investors are often surprised to hear that much of the necessary technology already exists -- and some of it is already included in the latest new cars.

For instance, Ford (NYSE:F) offers a system that help drivers with parallel parking. That system uses sensors to help you guide the car into tight spaces. But as Motley Fool contributor John Rosevear explains in this video, Ford this week showed a new system that takes it one big step closer to true self-driving -- by parking your car for you even if you're not in it.