Factual error: "Lucille" is listening to a transistor radio when she washes the car - clear from the size and because the music starts as soon as she turns it on. The first transistor radio wasn't available until 1954, and this movie is set in the very early 50s.
Suggested correction: Another correction points out that this film takes place post-Korean War, so after 1953. The radio fits the timeline.
Factual error: In the opening when the men are hacking away at the straw on the side of the road you can see a late sixties blue station wagon driving through the intersection in the background.