This episode contains several references to the State of Michigan; the four businessmen who hire Rockford are from the fictional town of Deer Lick Falls, Michigan. Richard Sanders plays a character named "Samuel Romney." George Romney (father to 2012 presidential candidate Mitt Romney) was governor of Michigan in the 1960s. Later, Angel visits the four businessmen in their hotel room, under the ruse he's from the coroner's office, and goes by the name "Mr. Milliken." William Milliken was the governor of Michigan immediately after George Romney, and was in office during the airing of this episode.
When Jim is barreling down the hill after his brake lines are cut, the costar's silver Vega backs out of a driveway halfway into the street, in front of him, and Jim has to swerve around the Vega.
When Rockford is driving round LA looking for the theater where Inga is working, they use old footage from an earlier show with the 1974 Firebird in it (you can tell by the grill). In that scene, you can see two cars that co-stars parked on the street, the silver Vega and the bronze '61 Thunderbird.
This story features men from Deer Lick Falls, MI. Several years late, an episode of The Greatest American Hero titled, " Here's Looking at You, Kid" features people from Deer Lick Falls, but that imaginary town is located in Minnesota. Stephen Cannell and Juanita Bartlett produced both shows.