After learning that Herman's "detective certificate" is from Mexico, Grandpa sarcastically says, "My son-in-law, the wet-back detective." Reruns of this episode bleep out the racial slur.
The composite drawing of the suspect Herman is supposed to follow was actually drawn by Fred Gwynne who was an accomplished artist.
Lily collects for their favorite charity: 'Bundles for Transylvania'. Actually, as part of the British War Relief Society (BWRS), American citizen Mrs. Natalie Wales Latham, in 1940, started 'Bundles for Britain' as a knitting circle that ended up expanding to the point of shipping USD 1.5 million worth of goods and raising USD 1.0 million in cash. As a recognition, Mrs. Latham was honored with the Commander of the Order of the British Empire in 1946.
The title is based on the cliché used by detectives (which Herman Munster wants to be), policemen and those chasing an individual when they quickly leave in an automobile. The person jumps into another automobile and yells: "Follow that car!"