Every vehicle has the own camera.
But developers often cares a little for it. Cameras are not in cockpit and driver can not see inner details like window or control panel. Some wagons camera has blank view (below the roof and no window).
For example Scheduled bus developed correctly.
I wish a possibility to move inner camera within vehicle to another place then fasten it (for this current vehicle only) like any other customizable property. A gismo can do the job.
For example correct cockpit for steam vehicles in the linked picture.
Thank you, in advance!

You can do this yourself.

I am using this too but it is a partial solution only.
Full solution: active camera must react to turning commands from keyboard like free cameras.