Set it up with a full, AI-only grid on an endurance-length race and leave it going overnight. By the morning the AIs are a lot better, at least at the driving part.
I always remember my mate gushing over Gran Turismo 4 on his PS2, and how it was the best, most realistic sim ever and had the most amazing AI ever.
I stopped my car on the track and watched the AI smash into the back of me at full speed every lap, with no indication that they even knew I was there.
Just wait till all the Finns come in here and regale us with stories about the whole family pissing on a shark, burying it in the ground, then digging it up 6 months later and eating it.