[Jonesy96]

In all honesty, I would say this is a bad idea. Reason is I'm pretty sure vehicle doors are not synched. As a result, a vehicle door might be open for one person, but not for another. To have the door so that it is locked for everyone, regardless of doors being opened/closed on different player's screens, see the below:

https://sampwiki.blast.hk/wiki/SetVehicleParamsEx

If you need further help with the function, just hit another reply and I'll give you a hand