[fredophile]

So your first solution means that NPCs can't interact with doors. What if your game needs NPCs to be able to move around freely and not be trapped in the rooms they spawn in.

Your blocked door solution also has some issues. How do I represent the state of a partially open door? Can a partially open door block bullets? Can I move through a partially open door? Can NPCs? What happens if the car moves towards the door while it is partly open? What if the car moves away? What happens if I try to interact with a partially open blocked door? What happens if I try to interact with a partially open unblocked door?