I know it's not the easiest car to drive in the game, but why can't the AI handle the RAC? I've been developing an easy to drive generic set for it, and like to have some computer opponents to test with, but the AI can't get anywhere near me no matter what set I have them use or how much time I give them to train. On some tracks, they're lucky if they can turn a clean lap and they'll keep making the same mistakes over and over again. illepall With the other cars I've tried, I can let the AI run a few races and then they're quite good, even fun to watch race! Impressive! But not with the RAC. Any theories?

They don't account for the tyres changing, I've noticed they are pretty terrible with the RAC. A few too many slides and the tyre temperature increases, grip decreases and from then on they slide more and get worse.
Makes em look like they're practicing dounuts

chicanes seem to screw them up the most, like any of the FE or SO tracks, they're always slapping the wall, spinning, or just hopping too big of a curb and spinning. Cold or hot tires. And then yes, it's donut time. I've even tried to park my car in front of something they like to hit, hoping that they'd have some programming to try to avoid me and then maybe learn where to go, but no, then I just get creamed. lol

Train them for a while with low fuel. Then put full tanks in and watch them overshoot every corner.
I think they said it above. The AI drivers can't correct for changing conditions too well. Plus, the default line they drive on some tracks is just not right and any small change they go off.