NavMeshAgent Desired Velocity always 0

This has been annoying me for ages I have not changed anything that I think would cause this. The car goes in the direction it is facing and flies of the track.

Code:

 using UnityEngine;
 using UnityEditor;
 using System.Collections;
 
 public class RivalPathFind : MonoBehaviour {
 
     public float sensitivity;
 
     NavMeshAgent agent;
     Transform wantedPos;
     bool setTarget;
 
     // Use this for initialization
     void Start () {
 
         wantedPos = new GameObject().transform;
         wantedPos.name = "WantedPosition" + " " + gameObject.name;
 
         agent = GetComponentInChildren<NavMeshAgent>();
     
     }
     
     // Update is called once per frame
     void Update () {
 
         wantedPos.position = (agent.desiredVelocity * sensitivity) + transform.position;
 
         if(!setTarget && GameObject.FindGameObjectWithTag("End")){
         
             Debug.Log("Hi");
             agent.SetDestination(GameObject.FindGameObjectWithTag("End").transform.position);
             GetComponent<RivalAI>().target = wantedPos;
             setTarget = true;
 
         }
 
         //Debug.Log(agent.destination);
     
     }
 
 }