I've not read thru all the threads but only the first ones. Sorry if this was asked some time ago. This feature might be difficult to add, since it will implie having lots of vehicles on screen, navigation and physics. Perhaps having some kind of LOD on physic to make it happen. Would be really cool to drive a vehicle in a city with lots of cars. There would be a lot to implement on the NPC side (follow road regulation, navigation system and limiting the physic for the non-player cars). Since I saw the promotion video, I just hope to see a car driving game that implement this someday!
I think this won't be really hard to make, but it will be very laggy. Just try to spawn 10 cars and see how much your computer lags. Then think about your opinion again. But of course this is a good idea, but it will need much optimization.
Well something that could happen is that the AI cars would be lower quality than the others, making the game not slow down too much.
just loading up the visible bit and not the collision bit until the car is close, then it loads out of the ram and the collision is done