This episode is the source of several scenes used in the opening credits of the show - the sequence where a race car engulfed in flames goes over an embankment, and a three-part shot shown on a split-screen, of Mannix driving a race car along with scenes of the vehicles during the race.
The file footage of the racing scenes are from Riverside International Raceway, Riverside, CA.
The plane seen at the end is a 1966 Champion 7GCAA also known as the Citabra 150. Registration # N699DM, Serial # 56.
The background music in the middle of the episode is apparently not Herb Alpert and the Tijuana Brass- It does not trigger any hits in music recognition software. The same tune also appears in season 2, episode 6, "A Copy of Murder," during a lounge scene at 22:14 in. It's possibly a non-published piece composed and performed specifically for the Mannix series.
3 cast members from Star Trek TOS: Jill Ireland, Sabrina Scharf, and Emily Banks.