Gmod DarkRp Locking System

For a while now I have been trying to figure out how to make it so on my DarkRP server i can have lockable entities. I’m trying to make a few vehicles lockable. The problem is that they are entities and do not lock the same way vehicles do. I have seen servers where for example WAC aircraft vehicles are lockable (WAC aircraft’s are entities). So I know it is possible I just cant figure out how. Any help would be very appreciated.

See Developer Discussion for help threads, thanks!