Thanks guys!
I have made a small tutorial about getting the right size and position of the traffic vehicle in game when you hit it. I hope you like it.
The steps:
1. Open Zmodeler and show the BODY_H only.
2. Hide the side mirrors and make sure the main body is shown like this.
Note: The same thing is applied on spoilers, roof scoops, light bars,...etc!
(You should do that if your vehicle contains these parts and to get the right values!)
3. Copy the values from the Dimentions and right them
down to the Size line as you see them.