While driving to Milwaukee from Madison on Father's Day, I had Navigate on AutoPilot engaged. The car had moved into the right lane because the left lane was running slower (go figure). We were passing the cars on the left when one decided they were going to move into the right lane. They were right next to us and AP suddenly swerved towards the warning track. I had my hands on the wheel and immediately took control, but my Tesla saw the car coming way before I would have and I am pretty sure we would have been sideswiped. Pretty darn cool!