Herbie / Maggie's win in the final race felt cheap
I felt this was poorly handled in the movie really; but since Herbie can't really match Trip's stock car speed (the one Trip let's Maggie take for a ride and she gets all exited about), then they have to make Trip have an accident in the car so that Herbie can win.
It would have been better if Herbie had won a straight race against that car due to the build up / rivalry that was set up (Herbie getting jealous/sad about Maggie riding and wanting Trip's car and such).