The red, open-cab truck driven by county agent Hank Kimball was a Ford Bronco Roadster. It was updated yearly through the run of the series (1965-71), as soon as a new model became available.
Eustace Charleton Haney:
These are gen-yew-wine Siamese Catfish.
Oliver Wendell Douglass: SIAMESE CATFISH?
Eustace Charleton Haney: Well, they're still in the pussy stage.
In the opening song when Oliver sings "You are my wife," he reaches for Lisa with his left hand. As Lisa sings "Goodbye city life," Oliver reaches in and grabs her with his right hand.
In some episodes, the opening credits appear in unusual locations (e.g.: chicken eggs, towels, writing on walls, breakfast items, newspaper headlines). In other episodes, the characters - particularly Lisa - react to the appearance of the credits superimposed over them or next to them.