School buses, juggernauts, farm tractors would have been greatly welcomed. The Artificial Intelligence of this game ranges from pretty good to darn stupid. The cops are pretty good, and the other cars are darn stupid. This is what I call 'ambient' Artificial Intelligence - AI that doesn't really matter, but adds to the overall gaming experience. The police AI is relatively good - but I have a feeling a little cheating goes on in the form of increasing the speed and altering the physics of the car.
Police vehicles seem to have an excellent ability for gaining speed at strategic moments.
I'd like to see a little more group action, I've seen many police cars take each other out in a mad frenzy catching me. The AI can be caught out quite easily if you drive into a car park - seems to confuse them endlessly. Although, in the game's favour it seems like they wait outside if they can - and only follow if they enter during a pursuit. Once time I was pursued by a police car in San Francisco, and I thought I'd be clever and dash into the nearest car park. I promptly killed the police car and ventured outside - where 3 more police cars were waiting for me.