Here's a video showing autopilot in action in a Tesla Model S.
And while these have become quite popular from Tesla drivers themselves, this one comes to us via Autoblog - so it's done quite well.
"Autoblog's Adam Morath demonstrates Autopilot on the 2016 Tesla Model S P90D. Autopilot enables self-driving in some situations on the Model S. Cameras, radar and 360-degree sonar evaluate traffic and road conditions, allowing the Tesla to autonomously steer and change lanes on behalf of the driver. But, in our experience, Autopilot is not perfect all of the time."
*Note: Definitely not a 2016 Model S, as stated in the description above. This is a 2015 S. The first 2016s will come out in...2016