Car damage

Hi,

i want to make a game with cars that can be damaged and have two questions.

So i think of a car that lost its bumber if it drove against a wall or even better at the first time the bumber hit the wall it will lost the contact from one side of the car and swing a little up and down or to the front or to the back and than if the car drove a second time against the wall the bumber fall down.

So i want to make a car that i can completly damge like in some other games.
With clattering engine bonnet and door that swing to and from the car.
Al things from the car can be battered.

So i think i can model such a car with al his piece parts from new ones to the battered.

Also i think it must be possible to change the pieces, i.e. the bumber if it hit the wall to the next bumber that looked battered.

But i am not a programmer so maybe someone can help me to script something like this.

I have bought the two books (3D game programming all in one 1 and 2) and will work true them step after step.
But i will model something for my idear also and make some tests now.

I have tge and the car pack so making a car is not the problem.

So here are my two questions:

1. How can i ad i.e. a bumper to my car in three different forms (new, damaged and scrap) and change them after a collusion ?

2. How can i make them looking linke they use pysics so that the damaged pieces swing if the car starts or brakes (i think the pysics in tge is not mature enough) ?

Thank you
Mathias