I have to say, that is some brilliant scripting. Partly because it gives a very realistic look, but also partly because it fills my British obsession of proper queuing :p (I could not believe when I went to Spain how they were pushing past each other at the doors!)The door script is partly custom, edited such that when the doors are opened the exit is marked open, but the entrance isn't marked open until there are no requests by pax to exit. Basically the same method used to keep the rear door of default buses open until they've finished boarding. You could implement this in other buses if you wanted, but simply replacing the existing scripts with the C400R's one could well break some things, so you should be prepared to do some code splicing.