What is "good"? See this is a problem that will always plague single-player action in games. You have to be "good" to beat them now. Not any bum off the street is going to beat the AI when everything is set to the hardest situation. I got friends who can't even get the cars to the first turn (depending on the car) so beating the AI is impossible.
"Good" is so relative. Good by who's standards? Do you mean "good" as what Lewis Hamilton would call another driver on the grid with him or "good" as in what you consider good? If we go by what you consider good who's to say your definition is any good, no pun intended.
See where I'm getting with this? I'm not defending the AI in the game. It's pretty good but not manna from heaven or anything. But it's a tricky situation to deal with.
They could make the AI foolproof but you'd never win a race. They could make the AI take every turn at the optimum speed and angle of attack and you'll never EVER win a race.