I'd say go to data persistence if you want the easier method for that.
http://wiki.roblox.com/index.php?title=Data_store
*Unlike Data Persistance, Data Stores cannot save ROBLOX instances directly. For example, calling DataStore:SetAsync("key", Instance.new("Part")) will throw an error. You should write a function that converts the instance to a table or string. *
So for what you would do for datastores, is make each part of the car converted into a string(So you'll have to make a script that reads that string and creates the brick for X car).