Allow dust follow rcCar

Questions
1

i added shader

const dust = new THREE.Points(geometry, material);
scene.add(dust);

it updates in gameloop

  const positionAttribute = dustGeometry.getAttribute("position");

  for (let i = 0; i < count; i++) {
    const i3 = i * 3;

    ...
    if (positionAttribute.array[i3 + 1] > 2.5) {
      positionAttribute.array[i3] = (Math.random() - 0.5) * 8;

      positionAttribute.array[i3 + 1] = -2.5;
      positionAttribute.array[i3 + 2] = (Math.random() - 0.5) * 4;
    }

and there i use these lines to allow dust follow rcCar

let throughDiffDustAndRCCar = new THREE.Vector3().subVectors(new THREE.Vector3(dust.position.x,0, dust.position.z), new THREE.Vector3(samplePickRCCar.position.x,0, samplePickRCCar.position.z) )

 dust.position.copy({x: samplePickRCCar.position.x, y: camera.position.y, z: samplePickRCCar.position.z + throughDiffDustAndRCCar.z     })

the issue is that samplePickRCCar.position.z and dust.position.z are expected to be different to allow dust be shown in camera

what diff of vectors i may use?

dust expected to be in the end of the car, it depends of camera.y
and there diff between rcCar.position.z and dust.position.z to be shown in camera