The Lew Ayres character (Sinclair) several times throughout the show makes a point of saying he is 73 and not likely to make 74. At the time of filming Ayres was only 66, and in real life would live to be 88.
Lou Zivkovich, who plays Carey, is best known for posing in the nude for the July 1974 centerfold in Playgirl Magazine. Also working at the health club was Sharon Cintron, who plays the receptionist, and was the Playboy Playmate for May 1963.
The McMillan's home phone number is 536-6674, according to Inspector Jacques Arnaud. Enright's phone number is 856-8533 judging by what Sally punched on the phone.