Johnnies truck is a 1969 Land Rover 88" series II A station wagon. It was Randy Mantooths personal vehicle.
The backstory is the need for Santa Rosa to have a paramedic program. It aired Dec 25, 1976 and the Oct 11, 1977 Issue of the Santa Rosa Democrat Newspaper reports that a Paramedic program for the Santa Rosa area was approved "in concept" on Oct 10, 1977.
Unlike other episodes, this one starts out with the opening credits before the story begins. Normally, the opening sets up the story before rolling the credits.