A vehicle in an RPG or something that you could only use once once you bought it? Like, you wouldn't want people stealing it from the garage when you're away without paying so it could be set to NONE when it is destroyed.
One of the greatest benefits I forgot to mention. :o
This is will help me in making the purchasing system in the game mode I'm making. Vehicles can be bought once per vehicle spawn, but when they get destroyed, the team commander will have to buy another one.