Ошибка Assets\Scripts\CarController.cs(20,9): error CS0103: The name '_rb' does not exist in the current context

using UnityEngine;

public class CarController : MonoBehaviour
{

private Rigidbody rb;
public float speed = 5f;
private bool isClicked;

void Awake() {
_rb = GetComponent<Rigidbody>();
}

void OnMouseDown() {
isClicked = true;
}

void FixedUpdate() {
if(isClicked)
_rb.MovePosition(transform.position + Vector3.forward * speed * Time.fixedDeltaTime);
}

}