How do I script a data store system to save owned vehicles in game?

I have a spawned system that deducts value from a users leaderstats and spawns the vehicle by cloning the one in server storage. Currently when the player leaves, despawns, or spawns a new vehicle they are refunded partial amount of the money. I am wondering how to make it where if they leave and come back they still can spawn their car for no additional charge and can own multiple cars at once.