!URGENT! Driving Game Like Art Based RPG !URGENT!

I am making a small game with a drivable vehicle the view is from above and I’ve made it with a tile based method, like Zelda. What I need to do is turn it into a game where you can drive around and the background moves with the vehicle like an art based rpg.

I’ve got the code for the vehicle and accurate hit tests and consequences all I need is the code to work.

Theres an art based rpg here: http://www.gotoandplay.it/_articles/2003/10/zelda.php?PHPSESSID=ea898fd9dd533727da60632455fff19f but I don’t know which code where should go where in my game from the example.

The art based source file is here: http://www.gotoandplay.it/_articles/2003/10/_zelda/OS_zelda_v1.3.zip

The code for the vehicle for convenience:
[AS]onClipEvent (enterFrame) {
// make the car go forward
if (Key.isDown(Key.UP)) {
speed += 1;
}
// make the car go backwards
if (Key.isDown(Key.DOWN)) {
speed -= 1;
}
// tells the car to slow down after the speed of 20
if (Math.abs(speed)>20) {
speed *= .7;
}
// you can change the rotation of the car to your desire
if (Key.isDown(Key.LEFT)) {
_rotation -= 15;
}
if (Key.isDown(Key.RIGHT)) {
_rotation += 15;
}
// here is where the hittest is for the boundary
speed = .98;
x = Math.sin(_rotation
(Math.PI/180))speed;
y = Math.cos(_rotation
(Math.PI/180))speed-1;
if (!_root.land.hitTest(_x+x, _y+y, true)) {
_x += x;
_y += y;
} else {
speed *= -.6;
}
}[/AS]