It's understandable you mistook the AI for all having the same setup; the AI basically calculates an "ideal racing line" first (actually it's a mixture of 2 racing lines, dependent per driver, to give them some character), and then it tries to follow that line as best as possible. However, these lines are not dependent on car setup, so that's why you didn't notice! Making them different per setup would actually be faster @ optimized for the setup, but that was just a bit too complicated for me :)
If the game were to ever become popular, I would definitely fix bugs like the wall bug, but alas, it's not to be! (well I mean, it could still happen, but it's unlikely I think). It's nice of you to consider the possibility of the game becoming popular though!
Thanks again and hopefully you'll like my future projects too! Cheers :)