Well, in some ways we already have robot cars. Audi and VW and others already have a lot of driver assistance features like blind spot checking, rear camera, etc. Some cars even steer autonomously to assist with parallel parking. However, if you're hoping to see fully autonomous driving in consumer casr you're going to be waiting a while. There are a lot of regulatory and comfort/psychological issues with such systems.

Disclaimer: I spent last quarter working on a driver assistance system on Junior for changing lanes on the highway.