That is great. You should also make the back wall of the cab photorealistic too. That, along with the higher resolution side texture this exterior is in dire need of, will make the exterior of this train pretty much perfect. To make the interior equally good, you should make a better ceiling with a photorealistic texture, and create some ambient light that is realistically yellowish like in real life. Currently it really looks like the interior lights are turned off, it should look like they are on. But it might just be my imagination too, so just add a photorealistic ceiling texture where the lights can be seen on. If that still does not make it look like the interior lights are on, then add the ambient light I mentioned.