If i understand it, you wanna make something like a marker to show damage. You could use the script of the project i3dlocationtoscreen.

void Main()
{
   Vector3 targetLocation;
   Vector3 screenLocation;
   //get car location
   iObjectLocation(OBJ_44,targetLocation);
   //add some offset to car location
   targetLocation.y += 1.5;
   //get corresponding screen location
   i3DLocationToScreen(screenLocation,targetLocation,OBJ_22);
   //place the label there
   iObjectLocationSet(OBJ_0,screenLocation);
}

OBJ_0 is a textprint or a sprite
OBJ_22 is the camchase
OBJ_44 is the car

Try it, i think you will need this

But I don't wan't zoom in or zoom out the sprite with i3DLocationToScreen Function. there is another Function for that don't change zoom?