In this case, the car environment is neither a source of illumination of its interior, nor the source of reflections shiny parts, as it is located just outside the window of the car. That is, in fact it's just the volume background and no more than that.
So, zamorchivatsya with the idealization of the tunnel completely not worth it.
In addition, if you traveled at least once in the subway, you could see that if you do not look purely at the window and look at the screen through the interior of the car, the relative difference in illumination inside the car and it is such that even a lighted tunnel seems to be just black.
the next thing you be taken into account, this is what will be seen through the window only side of the tunnel wall. Therefore, it is not necessary to model its upper part and especially the track😁
Turning directly to your question, it is easier to make this model of lamps and their luminous ceiling appoint mat. For more realism, you can even apply a texture that simulates the glow anchored in the center of the ceiling, and a small attenuation on its edges. You can do a simple Gradient Ramp, passing from pure white to light gray, which is necessary to invest in self-luminous mat texture slot.
Ideally, they should be supplemented also VRayLight in Plane mode, simply by setting them to shades and pointing in the right direction.
Here look, as did the mOPs in its version of the car. In fact, most of the tunnel lighting, nothing is different from the interior light of the car, having practically the same shape.
But again, make sure that all the necessary you angle will be seen, these diffusers to do extra work on their vymodelivaniyu. Perhaps they do not would not be seen from one angle, and will be sufficient to simply place a few lights o rectangular tunnel in the right places.