Not a GOOF at all...

That section states...

"The pickup truck Casey and Athena drive to Frank's house has a Tennessee license plate on the rear when they first acquire it. After they arrive in New York, when Athena returns with the truck in the woods near Frank's house, the front of the truck has a New York plate."

In reality they are two completely different trucks, the first Chevy pickup truck is a more modern burgundy full size truck with Tenn. plates, the truck Athena shows up with in the woods is an older style Chevy(short bed possibly) that has silver sides, Athena most likely stole/borrowed it near where Frank lived, because she's a little girl robot with a penchant for auto theft as seen earlier at 'Blast from the Past' when she steals and hotwires a Cadillac. I believe they mention older Frank lives in NJ, so it would be easy to find a truck with NY plates on it. Not a goof at all...

"Well, isn't this place a geographical oddity! Two weeks from everywhere!"