I can confirm that (on at least my copy), this works on the PS2 version! With some problems...
First is obvious, you can only use the Stand-alone script since certain things have changed between versions, namely the ID numbers (More below), and so using the PC's other scripts will break it (the beginning of the game is full of snow!).
Second, you must enter the moped(Scooter) Manually, as warping into it will trap you in it and it won't move...
Third, All the Id's are wrong, Only Id's 272, 273, and 274 work, and correspond to PC Id's 296, 297, and 298 respectively. I had to use cheat engine (I'm using PCSX2.) to force the spawner to use lower Id's, which allowed me to spawn the rest of the vehicles.
Also, I don't know if it is the same on the PC version, but the Police bike works fine every time if I try to enter it Manually first (even though you can't really enter it that way), and then warp into it.
Obviously, this wasn't meant for the PS2 version, but it is awesome that it works none the less.