The Firebird that gets wrecked is an older model than the one that was used in the rest of the show.
Close to the end of the show when Rockford's 1975 Pontiac Firebird ends up nose-down off the dock, it is clearly a 1970 to 1973 car. The front end is different and the blinker is down below the front bumper. As the camera pans past the rear of the car, the smaller tail lights are those of a 1970 to 1973 Firebird. (The 1974 and 1975 models have much wider tail lamps.)
The phony agent Bettingen's car is described as a green Ford 2-door. This car was actually a 1974 Mercury Montego.
It's $23.74. She lacks $1.26 from $25.00.
Los Angeles police cars did not have mechanical sirens in the 1970s.
The last name of FBI director Clarence Kelley is misspelled as "Kelly" on Bettingens and Rockfords federal IDs.