Acade Mode Dirt Tracks - Only 2 cars?

[Beezer215]

I know dirt tracks and rally isn't popular amongst most here. I am new to Gran Turismo Sport (one week now) but have been playing since the very first one.
Is there seriously only just one car to race against on the dirt tracks in Arcade Mode? Am I missing something? Do I have to unlock something?

Thanks for any help.