Hi,
Sometimes during some boring hours on the servers, sometimes I let the AI race instead... and it tends to get boring, that one knows that ALL the AI drivers behave virtually the same.
My suggestion for the AI is to allow the user to define a 'characteristic' that changes the AI's behavior. For example, if I chose 'Driver A' to be 'Aggressive', then he could care a little less about getting his car damaged when overtaking. Or if I set 'Driver B' to 'Cautious', that he drives slowly and overtakes ONLY if he is 100% sure if he can do it unscathed.