Why doesn’t my Plymouth Duster have a passenger side mirror?

Had a Chrysler 300 as a rental last week. Not only did a yellow triangle appear in the mirror when someone was on either side of you but the car steered it's self! It sesnses the lane lines an steeres the car! At first I thought "what great alignment, I hardly have to correct" It was when I felt the car steering wheel tug a bit that I realized what was going on. I literally let go of the wheel (just loosened my grip but kept my hands around the wheel and the car steered through the turn! It did, after a short period give me an alarm and the dash said "place hands on wheel) and the car slowed down. Scary business.