Although Jim Rockford always drives a current model Firebird, many episodes feature stock footage shot with older models, especially in the 1975-77 seasons.
Throughout the series, the Los Angeles Police Department responds to calls at Rockford's trailer in Malibu although it is not part of their jurisdiction. The Los Angeles County Sheriff would be the proper agency.
Throughout the series, Los Angeles police cars are depicted as having 2 rotary beacons; in the early to mid 1970s, Los Angeles police cars had 2 red lights with amber flashers on the back.
Jim frequently tells people that he doesn't "have a license" for his handgun. He didn't need a license to carry it. Very likely, however, the firearm wasn't registered in his name, which was why he was always reluctant to be caught with it.
Throughout the series, it seems that Jim taking a ride from his trailer in Malibu to downtown Los Angeles takes about ten minutes. In reality it would take about 45 minutes, if the traffic was light.
Throughout the series Rockford's trailer, parked in a parking lot, has electricity and running water, yet there is no evidence of a power line or plumbing attached to the unit. Also, it often changed position: sometimes it was parked parallel to the beach, and sometimes perpendicular to it.
There are numerous scenes of Jim or Rocky (or both) crossing the Vincent Thomas Bridge over Los Angeles Harbor. Since neither one lives anywhere near it and the episodes don't indicate that they are going to the harbor or San Pedro, there's no reason for this.