It should be event output-based, IMO, and have prefs for spawning at bricks vs spawning at players. Also a pref for enabling whether players can use /cmds to spawn a vehicle to player or not.
OnPlayerEnterZone >> NB:VehicleSpawn >> SpawnerGUI <bool> (At Brick)
OnVariableTrue >> Player >> SpawnerGUI <bool> (At Player)
Where the boolean is just unchecked to start out with no saved changes, and always starts with a "standard" setup, and checked means it preserves the settings from the last update.