Driver Parallel Lines (PS2) - Attack of the shifting vehicles

The Playstation 2 version of Driver Parallel Lines has some sort of easter egg that swaps some vehicles for others when they're not shown to the player. I found this phenomenon, which I think was more likely an intentional act of trolling by the developers of Reflections Interactive (today Ubisoft Reflections), in the PS2 version of the game, but I don't know if also happens in the Xbox version, but doesn't happen on PC.