I'd check the readme's if you haven't already. Apart from that, sorry, I don't know how it works.
Problem: My championship doesn't show up in game!
Cause 1: You have the wrong rFm loaded in game.
Solution 1: In the Main Menu of Game Stock Car 2013, press one of the arrow buttons in the bottom-left corner until the name of the correct rFm for the cars to be used in your championship shows up.
Cause 2: You terminated the program premeturely.
Solution 2: In the folder that the batch file is located in, go into the tempfiles folder and there may be a file with the extension .aos. Depending on where the batch file was terminated, you can manually copy it over to the rFm folder in your Game Stock Car 2013 install. However, I recommend just starting again.