Oh I see, of course, so what was Rhys talking about when he mentioned editing the model.cfg, etc? What's that all about?
If you know what you're doing, and if they happen to line up properly (which is rare but as the C400 and C400R are based on the same model they will), it's possible to transplant components of one bus into another bus.
That means if you'd bought and installed London, it will be possible to take the CCTV screens from the London version of the bus and fit them to the regional version - I'd imagine that a mod will spring up on the forums relatively quickly to do just that if you wait a while after the release, too. You will need to have London installed for it to work though.