Hazel incorrectly states that this his her first car. She purchased a 1920 Model T from the Johnson's in the episode, "Hazel Buys A Model T" (Season 3, Episode 16).
Hazel claims "Chrysanthemum" is her first car purchase but she bought a car from the Johnson's in an earlier show (Hazel and the Model T).
Near the end of the episode, as Ted is backing his red truck out of the driveway a crew member's hands can be seen pushing the truck (lower left). Moments later reflections of a boom can be seen in Hazel's car windshield and then the boom itself becomes visible (upper right).