You can copy this game

Copying a game isnt simple unless the publisher specifically allows it. If you really want to, it might be worth taking a look at Dex, you will need an executor for it, but it can in most cases save parts of the game. You should know however, that on even the best of executors, you will not get serverside scripts. Only LocalScripts and ModuleScripts can be decompiled, as serverside scripts never get sent to the user (its called serverside for a reason). If your wishing to preserve the functions of the cars, then your outta luck. I can tell you however, it probably wouldnt be too hard to find a pre-existing vehicle script, modify it, and "transplant" it to the car.