This happened to be on a highway when driving my friends car with all these assisted driving "features" while in cruise control. I was going up a small hill and for whatever reason there was a car stopped right at the top that I couldn't see. So the car slammed the breaks while I was in the middle of swerving out of the way. Which caused me to swerve more than I had intended. After I regained control it removed the breaks and attempted to return to the 80mph I was at previously which caused more problems because I wasn't ready for that.
I am now of the opinion that a car should never under any circumstance drive for you. If a car has cruise control it should cruise control you into a wall. That I can at least anticipate.