Since damaged models can't be extracted, i created this damages system from scratch in 3ds Max.
Originally i opted for "pre rendered" damaged meshes, and the original meshes were replaced at runtime, after a collision.
After reflexion, i chose another method, more convenient to use. The vehicle is deformed by using a few blendshapes.
So i can control which parts are affected by collisions.
With the old method, i separated the car into several parts, but with the blendshapes, I don't need to do it anymore.
The vehicle physics package i use, has a damages function but i wasn't visually satisfied by the result, so that's why i created my own system. I wanted a similar visual effect, like in the game.
So some screenshots:
As you can see, it's possible to damage only a side.