There is an inside joke in this episode, as Don Knotts is introduced as a recurring character. In "Barney's First Car" on "The Andy Griffith Show," Don Knotts, as Barney Fife, buys a car that turns out to be a lemon. In this show, Knotts, as Ace, buys a lemon as well, only this time he is accused of murdering the person who sold him the car.
First episode to feature Don Knotts (Barney Fife on The Andy Griffith Show) as his neighbor Les Calhoun.
The white Cadillac El Dorado convertible with the antlers hood and ornament little six shooters for door handles looks a lot like the very same car used in Blueprint for Murder (1972).
This is your chance to see Don Knotts driving a DeLorean which is The Lemon in which this title refers.