1959 Chevrolet Station Wagon television commercial

I study vintage television commercials for their cultural markers. Automobiles are especially interesting markers because of the various roles automobiles play in society. The narrative in this commercial centers on Mom's use of the automobile, so some of the business created to establish that is peculiar. For example, why would she put the groceries in the front seat? Putting Dad and Junior in the back seat and Mom behind the wheel establishes the point that this is her car but where are they when they pull off at the end? And why is the salesman still in the car?