How about the end of Vanashing Point? What person that went to see that movie wouldn't be able to tell that crash car was a Camaro and not a Challenger? Don't get me wrong, I am glad they didn't lunch a Challenger for the scene, but that is one that always bugged me.
There is a terrible movie called Out for Justice, it came out in the early 1990s. I only watched it because there was supposed to be a Buick GNX in it. Man I got ripped off! Some guy says "Take the GNX, it's parked at blah blah blah", then it just turns out to be a regular Grand National. If you are going to get that specific in the script to mention a car that they only built 500 of, you'd think they'd at least try to fake the real thing.
Bonus points to larrybuck or anyone else if you know what TV series actually featured one of the '55 Chevs used in American Graffiti / Two Lane Blacktop in one episode. To be honest, I can't remember myself, but there was a time when I knew this without having to google it lol!