In an acting career that spanned nearly seven decades and well over 100 different roles, Celeste Holm appears only one other time with David Janssen, an appearance that is also a part of this same series: Concrete Evidence (1967).
There is no Encinas county in California.
This is the third of five appearances Rodolfo Hoyos Jr. makes in the series and the third of seven appearances he makes on screen with David Janssen, the last two appearances occurring in Operation: Deadhead (1971) and Elegy for a Cop (1975), respectively.
This is the first of two appearances Lawrence Montaigne and Byron Morrow make in this series, each time in minor roles and each time in separate scenes in the same episode, their second and final such appearance occurring in Conspiracy of Silence (1965).
The sports car is a Jaguar E-Type, known in America as an XKE. They were produced in England from 1962-75. The later models were offered with a V12 engine.