I made some further adjustments to the AI and they aren't leaving me like I'm racing a Prius anymore. It's good enough for me to start near the back of the field and make it up to P2/P3 before doing something stupid and finishing in P4. As I become better I'll adjust the AI. Good fun so far, I don't think I could go back to Forza 7 now for fear of adopting some bad driving habits.