Their isn't really any given error for why this happens, I literally receive no error on what caused it.
I went into creative mod to make things easier for testing, I did it with all the vehicles, upon driving after 30 seconds with a vehicle the game freezes and then boots me out of my own server. Although when playing on my own world that isn't a multiplayer world their are no crashes at all. I would love to have this added to my server rather than adding the Ultimate car mod ( I don't really like that mod if I'm being honest) if you can fix it, it would be lovely

never mind, it wasn't your mod, it happened with another car mod. I will have to figure out why this is happening though