Back when I worked at a dealer (many years ago) one of the “perks” was I could drive any car on the lot for $400 a month. This was a Chevy dealer so anything from a Corvette to a Suburban to a Cavalier. But the car was never mine, I had to return it every 3 months and pick a different car from the lot. That car was then sold so obviously no modifications were allowed.
I have no idea if that’s what’s going on here, not even sure if that was a normal dealer practice or just something our dealer did, but I figured I’d throw out a wild guess.