I assume they're just running Assetto Corsa. There are tons of tracks and add-on cars available.
http://store.steampowered.com/app/244210/Assetto_Corsa/
I run it with these:
https://www.amazon.com/gp/product/B00Z0UWV98
https://www.amazon.com/gp/product/B00Z0UWV3O
(Don't even think about running it with a keyboard. It's more of a realistic simulator than a game.)
It's fairly straightforward to create new tracks if the CAD drawings are available. Most of the US tracks are developed by individuals and have to be installed as add-ons. I haven't been able to locate the NCM track, but I'm betting we'll see the NCM track in the near future since they have this setup now.