I am starting this thread here because I think its a good place because its closely related, not in the expectation that this is an issue the mod authors of animated vehicles should solve but to raise the awareness and collect ideas for a solution.
I have not tried all of the NPC mods out there, but in the case of Knox Event Expanded, there is this weird glitch where the animation of vehicle doors is not triggering properly. The NPC actually close the doors when leaving the vehicle, but appear to be open visually. There is a little trick to work around this by getting in and out again of the vehicle in the right timing which closes the doors, but that is still as annoying as going around the vehicle and open and close them manually all the time.
So I am wondering if anyone knows the exact reason for this glitch and if there might be a permanent solution to fix it. It appears to me that there is a general issue with some animation in the game that can get stuck in the vanilla game, like zombies that get stuck in the animation on killing.