How do you create an unlock vehicles System?

Easiest way without using DataTables for your car specs/infos etc.;
You can set a UnlockLevel/UnlockPoints variable for each car and you can block player to select/buy that car or hide car from store completely if player doesn’t have enough Level/Points.
I don’t know how you designed your car select system but, for example, if you spawn cars to StoreMap you can hide them after spawning by getting UnlockPoint and comparing with Player’s points. If player doesn’t have enough points you can simply use SetVisibility = Hidden.

Other way to do this is using DataTables. Which means, you hold car info such as UnlockPoint, Price, MaxRPM, VehicleClass etc in a DataTable and while listing cars on store, you can compare UnlockPoint from DataTable and Player’s Points and if player Point’s are lower than UnlockPoint you may not spawn vehicle at first.

Another easier method of DataTables can be this;
Instead of using complex DataTables you can make an Float array.
For example;

CarUnlockPoints variable, Float, Array

Index0=500

Index1=750

Index2=1000

and so on. Each Index can point to a car.

Index0 => Mustang

Index1 => Camaro

Index2 => Sephia <3

depends on your way of sorting cars.
Rest is same as DataTable option.

Summary;
You have 2 options.

-Spawn cars. and hide after comparing point variables. Or you can keep showing but blocking vehicle to be possessed.

-Compare point variables and don’t spawn car.