I was in the engine of my real car, so I couldn't answer fast enough to your questions.
You seem to have a camera activation problem.. It should activate for render the selected (pink) camera when you press ctrl+numpad0 but I noticed that I can't do it with my laptop. Do you have one? Blender does not seem to recognize emulated numpad keys...
The window on the right on your last screenshot with the FXR is not the "active camera" view, it's a common 3D view. To reactivate the active camera view, move your mouse pointer over the window you want to use and press numpad5 key.
Remember that the active camera has always a black triangle on it, the other have an empty one. The triangle is the best method to know what camera is the active one for render.
To get a reflective ground is easy, I'll try to quickly explain how to do it, tell me after if an illustrated chapter must be added in the tutorial to understand easier.
- Select the big circle that represents the ground in the 3D view
- Press F5 to enter the material menu
- depress "OnlySha" small button in the "Shaders" menu (need to expand it to see it)
- Enter the "Mirror Transp" tab and press "Ray Mirror" button
- Set a 0.2-0.3 value in the "RayMir" input. (this is the reflexion amount setting)
- Press F12 and enjoy
Note that the circle will be no longer transparent in the renders.
Actually I haven't tried to customize LFS models by inserting custom elements but it should not be hard.
- Find a wheel which its file is blender compatible
- Delete or move into another layer the default LFS wheels of the car.
- put the 3d cursor (left-click) where a wheel should be inserted (don't need to be accurate)
- perform a File>append (if the wheel comes from a .blend file) or a File>import and select the wheel file.
- The wheel should appear at the 3D cursor. Fine position it with the manipulation tools.
- Press shift+D keys to duplicate the wheel and re-position it for the three other wheel locations.
The last question is where to find custom wheels?
I'm glad to see that many people enjoy this kit, and like to insert a real background. So I'll try to find a good integration technique and post it later since it requires time.