Hover Car realistic.

Hello im trying to make a hover car realitic but i got much jumping or hover force then. can u tell me how to optimice? i wanna to make like this:

this is my wheel code for hover effect:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class HoverEngine : MonoBehaviour
4. {
5.     public LayerMask RaycastMask;
6.     public float MaxHeight=2;
7.     public float GroundForce=4000;
8.     public float Damping=2;
9.     public float Exponent=2;
10.     public float MaxAngleDrift=10;
11.     public Rigidbody Rigidbody;
12.  
13.     private float m_LastPower;
14.     private RaycastHit m_GroundHit;
15.     public bool HasGround
16.     {
17.         get { return m_LastPower > 0; }
18.     }
19.     public float Power
20.     {
21.         get { return m_LastPower; }
22.     }
23.     public RaycastHit Ground{get { return m_GroundHit; }}
24.  
25.     void OnDrawGizmos()
26.     {
27.         //  Hover Force
28.         RaycastHit hit;
29.  
30.         if (Physics.Raycast(transform.position, -transform.up, out hit, MaxHeight, RaycastMask))
31.             {
32.                 Gizmos.color = Color.blue;
33.                 Gizmos.DrawLine(transform.position, hit.point);
34.                 Gizmos.DrawSphere(hit.point, 0.2f);
35.             }
36.             else
37.             {
38.                 Gizmos.color = Color.red;
39.             Gizmos.DrawLine(transform.position, transform.position - transform.up * MaxHeight);
40.             }
41.  
42.     }
43.  
44.     void FixedUpdate()
45.     {
46.         // find force direction by rotating local up vector towards world up
47.         var up = transform.up;
48.         var grav = Physics.gravity.normalized;
49.         up = Vector3.RotateTowards(up, -grav, MaxAngleDrift*Mathf.Deg2Rad, 1);
50.  
51.         // check if we see ground below
52.         m_LastPower = 0;
53.         if (!Physics.Raycast(transform.position, -up, out m_GroundHit, MaxHeight, RaycastMask))
54.         {
55.             return; // no ground - no hover
56.         }
57.  
58.         // calculate power falloff
59.         m_LastPower = Mathf.Pow((MaxHeight - m_GroundHit.distance)/MaxHeight, Exponent);
60.         var force = m_LastPower*GroundForce;
61.  
62.         // calculate damping, which is proportional to square of engine upward velocity
63.         var v = Vector3.Dot(Rigidbody.GetPointVelocity(transform.position), up);
64.         var drag = -v*Mathf.Abs(v)*Damping;
65.  
66.         // add force and damping. Note that force is added at engine position
67.         Rigidbody.AddForceAtPosition(up*(force + drag), transform.position);
68.     }
69. }
70.  

 

bump

 

WheelCollider

 

WheelCollider sucks.
i want use raycast more realistic. wheel colider have bad car controll.