How does the setting of " A Good Man Is Hard To Find" control the conflict, characters, and point of view?

Much of the story is set in a car, as a 1950s family consisting of a father, mother, girl, and boy take a road trip to Florida. The children's grandmother comes along as well. She is an anomaly in this typical nuclear family and an old-fashioned person.
Being contained in a car or at The Tower, where they stop for barbecued sandwiches for lunch, intensifies the family dynamics: in the enclosed space of the car, the children come across as bratty, and the grandmother is only grudgingly welcomed. She shows herself to be a difficult and manipulative woman who thinks of herself as a lady and feels the modern world is going down the tubes. The American road trip setting also adds a comic tone to the beginning of the story.
The light-hearted tone changes abruptly with a change in setting. When the car heads down a deserted road due to the grandmother's mistaken belief there is a plantation at the end and then flips over into a ditch, the mood turns from comic to macabre. The family encounters the Misfit, and their lives are suddenly in danger.
Once again, the setting is contained. The point of view through most of this section is that of the grandmother, who is in the ditch where the car overturned. Since she cannot see what is happening, the murder of her family occurs at a distance. This puts the focus on her while she pleads for her life with the Misfit. As all her props are stripped away, the story narrows to a conversation between the Misfit and the grandmother.
Keeping most of the action confined to small spaces, such as a car or a ditch, heightens the dramatic intensity.

The story's setting in the American South in what is probably the 1950s informs the conflict between the grandmother and her society. She seems to be at odds with just about everyone else: her son, his family, and the Misfit. The only person she does not conflict with is Red Sammy, who happens to be the only other character that shares her perspective. She feels as though society has changed dramatically and for the worse—that people no longer have the same values they once did. Some would view this fact positively, but not so for the grandmother (who is never given a name, as though her age and generation are her defining characteristics).
The story is told from a third person limited omniscient perspective. It is important that we understand what the grandmother is thinking in order to really understand her character. Therefore, we get her thoughts and feelings. Typically, an author will choose to use a limited omniscient perspective in order to bring readers closer to a particular character, to decrease the distance between us and them.  Perhaps O'Connor wants to draw us closer to this character because she knows that her audience will be inclined to judge the grandmother harshly as a result of her age and time (setting). In allowing us to come to know her better, we can better understand her conflict with just about everyone around her.