The red mini dress worn by Christine Smith in this episode was previously worn by Deborah Grant (as Linda Simmonds) in The Psychobombs (1970) and prior to that by Susan Jameson (as Anne Stone) in The Sound of Silence (1971).
Straker's car gull-wing doors closing movement were operated by a propman out of frame. In this episode this is omitted, presumably for ease of filming wide shots.
At 30m 12s Virginia Lake jumps into a moving car. She is left of frame, camera pans right to follow the car, losing sight of Virginia Lake.
Suddenly, Virginia Lake jumps back into frame at such speed it can only be her stunt double in the middle of a run.
This episode takes place in 1980.