//Realistic control of a car, the example is ActionScript 2 but can be applied in numerous other languages
spd = 0;
onEnterFrame = function(){
    car._y -= Math.cos(angle*Math.PI/180)*spd;
    car._x += Math.sin(angle*Math.PI/180)*spd;
    spd *= .9;
    angle = car._rotation;

    if(Key.isDown(Key.UP))spd += 1;
    else if(Key.isDown(Key.DOWN)) spd -= 1;
    if(Key.isDown(Key.LEFT)) car._rotation -= .5*spd;
    if(Key.isDown(Key.RIGHT)) car._rotation += .5*spd;
    if(spd < .5 & spd > -.5) spd = 0;
}