***Myth*** You must be able to see the flanks of your own car in your outside mirrors in order to have a reference.
Truth: Your outside mirrors are improperly adjusted if you can see the sides of the car. Correctly adjusted, the three mirrors form a panoramic view much like one created with three slightly overlapping photos: The images on the inside edges of the outside mirrors slightly overlap the images on the outboard edges of the inside mirror. Properly adjusted mirrors reduce blind spots and reduce the need to look over your shoulder, which is a lot like closing your eyes while driving.