Basically how it works, is that it's a separate B-spec portion of the game. Six events, three different cars, maximum 16 cars per race.
If you host the race, you only get to use one driver. As the host, you can choose as many drivers up to the maximum.
The races can be controlled remotely, I've only used a PC so far, haven't tried other equipment/devices.
Details can be found in the Manual section from the Main Menu of the game.