From Rigs of Rods Wiki
A Cinecam and Camera section are required to make a functional Truck, Plane, Boat, or thingamajig to work.
The Cinecam is the camera you see inside the cabin or interior typically, This is the camera you can use the Numpad to control with.
The Camera is the setting that defines the general direction the cinecam + chasecam face when you are in-game.
Installing the Cinecam and Camera section
First off, you must find the three nodes you wish to use as your Camera nodes.I am going to use a generic chassis in this tutorial. Now that you've found the three nodes you wish to use, make sure you define them in your vehicle file in the format: Front, Back, Left. This is essential if you want a properly facing camera and cinecam. (Refer to attachment 1)
Secondly, To place a cinecam, after saving the chassis, the most easiest and simple way to make a cinecam is to place a node at the spot you want it at. The format for that is
cameras ;X, Y, Z, N1, N2, N3, N4, N5, N6, N7, N8, Spring, Damping X, Y, Z, Node 1, Node 2, Node 3, Node 4, Node 5, Node 6, Node 7, Node 8, 8000.0, 800.0
Now you are done, If you followed the steps correctly, you will have placed your cinecam and camera correctly in your functional truck :)