Hey,
I have an idea, I don't know if it is feasible, but I try it anyway.
It is a vehicle system, for example you have to pay a price, and we have access to a sports car (Turismo? Infernus? Or an NRG-500 bike?. (The access of the vehicle is temporary).
On the map, there will be a red checkpoint, which will tell us where is the location of the vehicle.
it would be although there is that the player who can see the vehicle.
When I say that the vehicle is temporary, is that as soon as we got into the vehicle, the countdown starts, and when the player leaves the vehicle the countdown stops. (You need save the number of minutes in the player's account).
I have some ideas in mind yet for this system but I don't know if it's possible.