We drove cars that can drive themselves - and cost only 20,000

Good news: You can buy a car today that will stop itself from crashing, keep itself in lane and even speed up and slow down to match the traffic ahead. Even better news: You don't have to go broke paying for it. Cars with this type of sort-of-self-driving technology now start at about 20,000. It's one of the auto world's most important and least discussed breakthroughs: Cheap starter cars are now being sold with some of the most sophisticated "driver assist" technology on the road. So how do they perform against today's "Autopilot"-enabled luxury cars, like the 130,000 Tesla Model S or 66,000 Volvo XC90?