Pontiac GTO at Hot Rods On Hampton (2023) in Butler, WI.
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Pontiac GTO at Hot Rods On Hampton (2023) in Butler, WI.
Pontiac G8 at Cassandra's Motorsports Open House (2023) in Pewaukee, WI.
Time Travel Rockford Style
According to WikiPedia: "Starting with the 1974 model year, Rockford would get a new model-year Firebird Esprit each year throughout the series, though they have identical "copper mist" color with a corresponding upgraded interior (and, occasionally, sharp-eyed car connoisseurs would spot the different model year cars used in various chase scenes that differed from those in an actual episode, especially in later seasons)."
So what's the big deal about Jim's car changing from scene to scene? Because in this case, it's not an older car in a newer episode. It's a newer car in an older episode. A 1977/78 model appears in This Case Is Closed, which aired October 18, 1974. This happens at the 8m4s mark and again at 10m35s, when the footage repeats. I have to imagine that maybe someone got a little cheeky with the DVD release; decided to paste this in for fun. Seems more likely than The Rockford Files getting their hands on a Pontiac prototype that wouldn't hit showrooms for another couple years.