After the Barbara Mandrell concert Jim & Megan (assumed) are seen driving down a road and they show the old dual headlight 76 Firebird in a night-time scene. Moments later the car pulls into a driveway and the new Firebird is seen.
Rockford is driving down a road in a 1974 Firebird (2-Round Headlights) and arrives at the destination in a 1979 Firebird (4-Square Headlights) [This is the same Goof as the first item above.].
When Meagan is on the hotel bed telling Rockford that she's in love with two men, her wrist watch is shown. It has the standard glass/plastic cover. It's a simple watch with no alarm buttons. A blind person would have no need for this.
During the opening credits, on Jim's phone answering machine, Jim receives a call from a bail bondsman telling him that his client has skipped bail and that Jim needs to forfeit the pink slip on his '79 Firebird. The Rockford Files stopped updating the Firebirds at model year 1978, as James Garner hated the redesigned front end of the 1979 Firebird.