If X player with the permission used the vehicle for onces. Players without permission can use the vehicle anytime.
And Players without permission can not open vehicle's tank that permissioned user used. That was an issue and u fixed it before. But players without perrmission were not able to open tank at all but now they can not open tank that permissioned user used for onces. 

Took me a couple of minutes to make sense of what you just said, but I updated it.

im not master of english but yea... tried to explain the issue of your plugin, thanks for the update