help with Car physics, etc

[Yorae]

How would you create accelleration for a car model, based on when you press the character's run button I guess is easiest? Also, what about creating the car's weighting and how it swerves, etc? Also, how would I set up the NPC cars to do what they do? ie. head for the finnish line, maybe purposefully slam the opponent into a wall, make the player lose if they aren't first across the line, etc? thanks