Hello Sengchor,
I think you’ll need to download the full City Sample project for the destruction system.
It’s an advanced system. (A lot of custom work done just for the City project as opposed to a generic supported/maintained vehicle destruction feature in Unreal Engine)
This video will help you begin to understand the systems:
An idea for a different approach: When one of these vehicles is “Destroyed” play Explosion/Smoke particle effect and change the cars material (paint/color) to a black/damaged one.