Below script is a car controller and i want the car to boost when hit a trigger object. Still new with unity T^ T

using System; using UnityEngine; using System.Collections;

namespace UnityStandardAssets.Vehicles.Car { internal enum CarDriveType { FrontWheelDrive, RearWheelDrive, FourWheelDrive }

 internal enum SpeedType
 {
     MPH,
     KPH
 }

 public class CarController : MonoBehaviour
 {
     private GameManagerScript GMS;
     
     [SerializeField] private CarDriveType m_CarDriveType = CarDriveType.FourWheelDrive;
     [SerializeField] private WheelCollider[] m_WheelColliders = new WheelCollider[4];
     [SerializeField] private GameObject[] m_WheelMeshes = new GameObject[4];
     [SerializeField] private Vector3 m_CentreOfMassOffset;
     [SerializeField] private float m_MaximumSteerAngle;
     [SerializeField] private float m_FullTorqueOverAllWheels;
     [SerializeField] private float m_ReverseTorque;
     [SerializeField] private float m_MaxHandbrakeTorque;
     [SerializeField] private float m_Downforce = 100f;
     [SerializeField] private SpeedType m_SpeedType;
     [SerializeField] private float m_Topspeed = 200;
     [SerializeField] private static int NoOfGears = 7;
     [SerializeField] private float m_RevRangeBoundary = 1f;
     [SerializeField] private float m_SlipLimit;
     [SerializeField] private float m_BrakeTorque;

     private Quaternion[] m_WheelMeshLocalRotations;
     private Vector3 m_Prevpos, m_Pos;
     private float m_SteerAngle;
     private int m_GearNum;
     private float m_GearFactor;
     private float m_OldRotation;
     private float m_CurrentTorque;
     private Rigidbody m_Rigidbody;
     private const float k_ReversingThreshold = 0.01f;

     public bool Skidding { get; private set; }
     public float BrakeInput { get; private set; }
     public float CurrentSteerAngle{ get { return m_SteerAngle; }}
     public float CurrentSpeed{ get { return m_Rigidbody.velocity.magnitude*2.23693629f; }}
     public float MaxSpeed{get { return m_Topspeed; }}
     public float Revs { get; private set; }
     public float AccelInput { get; private set; }

     // Use this for initialization
     private void Start()
     {
         GMS = GameObject.Find("GameManager").GetComponent<GameManagerScript>();

         m_WheelMeshLocalRotations = new Quaternion[4];
         for (int i = 0; i < 4; i++)
         {
             m_WheelMeshLocalRotations[i] = m_WheelMeshes[i].transform.localRotation;
         }
         m_WheelColliders[0].attachedRigidbody.centerOfMass = m_CentreOfMassOffset;

         m_MaxHandbrakeTorque = float.MaxValue;

         m_Rigidbody = GetComponent<Rigidbody>();
         m_CurrentTorque = m_FullTorqueOverAllWheels;
     }


     private void GearChanging()
     {
         float f = Mathf.Abs(CurrentSpeed/MaxSpeed);
         float upgearlimit = (1/(float) NoOfGears)*(m_GearNum + 1);
         float downgearlimit = (1/(float) NoOfGears)*m_GearNum;

         if (m_GearNum > 0 && f < downgearlimit)
         {
             m_GearNum--;
         }

         if (f > upgearlimit && (m_GearNum < (NoOfGears - 1)))
         {
             m_GearNum++;
         }
     }


     // simple function to add a curved bias towards 1 for a value in the 0-1 range
     private static float CurveFactor(float factor)
     {
         return 1 - (1 - factor)*(1 - factor);
     }


     // unclamped version of Lerp, to allow value to exceed the from-to range
     private static float ULerp(float from, float to, float value)
     {
         return (1.0f - value)*from + value*to;
     }


     private void CalculateGearFactor()
     {
         float f = (1/(float) NoOfGears);
         // gear factor is a normalised representation of the current speed within the current gear's range of speeds.
         // We smooth towards the 'target' gear factor, so that revs don't instantly snap up or down when changing gear.
         var targetGearFactor = Mathf.InverseLerp(f*m_GearNum, f*(m_GearNum + 1), Mathf.Abs(CurrentSpeed/MaxSpeed));
         m_GearFactor = Mathf.Lerp(m_GearFactor, targetGearFactor, Time.deltaTime*5f);
     }


     private void CalculateRevs()
     {
         // calculate engine revs (for display / sound)
         // (this is done in retrospect - revs are not used in force/power calculations)
         CalculateGearFactor();
         var gearNumFactor = m_GearNum/(float) NoOfGears;
         var revsRangeMin = ULerp(0f, m_RevRangeBoundary, CurveFactor(gearNumFactor));
         var revsRangeMax = ULerp(m_RevRangeBoundary, 1f, gearNumFactor);
         Revs = ULerp(revsRangeMin, revsRangeMax, m_GearFactor);
     }


     public void Move(float steering, float accel, float footbrake, float handbrake)
     {
         if (GMS.counterDownDone == true)
         {

             for (int i = 0; i < 4; i++)
             {
                 Quaternion quat;
                 Vector3 position;
                 m_WheelColliders[i].GetWorldPose(out position, out quat);
                 m_WheelMeshes[i].transform.position = position;
                 m_WheelMeshes[i].transform.rotation = quat;
             }

             //clamp input values
             steering = Mathf.Clamp(steering, -1, 1);
             AccelInput = accel = Mathf.Clamp(accel, 0, 1);
             BrakeInput = footbrake = -1 * Mathf.Clamp(footbrake, -1, 0);
             handbrake = Mathf.Clamp(handbrake, 0, 1);

             //Set the steer on the front wheels.
             //Assuming that wheels 0 and 1 are the front wheels.
             m_SteerAngle = steering * m_MaximumSteerAngle;
             m_WheelColliders[0].steerAngle = m_SteerAngle;
             m_WheelColliders[1].steerAngle = m_SteerAngle;
             ApplyDrive(accel, footbrake);
             CapSpeed();

             //Set the handbrake.
             //Assuming that wheels 2 and 3 are the rear wheels.
             if (handbrake > 0f)
             {
                 var hbTorque = handbrake * m_MaxHandbrakeTorque;
                 m_WheelColliders[2].brakeTorque = hbTorque;
                 m_WheelColliders[3].brakeTorque = hbTorque;
             }


             CalculateRevs();
             GearChanging();

             AddDownForce();
         }
     }


     private void CapSpeed()
     {
         
         

             float speed = m_Rigidbody.velocity.magnitude;
             switch (m_SpeedType)
             {
                 case SpeedType.MPH:

                     speed *= 2.23693629f;
                     if (speed > m_Topspeed)
                         m_Rigidbody.velocity = (m_Topspeed / 2.23693629f) * m_Rigidbody.velocity.normalized;
                     break;

                 case SpeedType.KPH:
                     speed *= 3.6f;
                     if (speed > m_Topspeed)
                         m_Rigidbody.velocity = (m_Topspeed / 3.6f) * m_Rigidbody.velocity.normalized;
                     break;
             }
         }
     


     private void ApplyDrive(float accel, float footbrake)
     {

         float thrustTorque;
         switch (m_CarDriveType)
         {
             case CarDriveType.FourWheelDrive:
                 thrustTorque = accel * (m_CurrentTorque / 4f);
                 for (int i = 0; i < 4; i++)
                 {
                     m_WheelColliders[i].motorTorque = thrustTorque;
                 }
                 break;

             case CarDriveType.FrontWheelDrive:
                 thrustTorque = accel * (m_CurrentTorque / 2f);
                 m_WheelColliders[0].motorTorque = m_WheelColliders[1].motorTorque = thrustTorque;
                 break;

             case CarDriveType.RearWheelDrive:
                 thrustTorque = accel * (m_CurrentTorque / 2f);
                 m_WheelColliders[2].motorTorque = m_WheelColliders[3].motorTorque = thrustTorque;
                 break;

         }

         for (int i = 0; i < 4; i++)
         {
             if (CurrentSpeed > 5 && Vector3.Angle(transform.forward, m_Rigidbody.velocity) < 50f)
             {
                 m_WheelColliders[i].brakeTorque = m_BrakeTorque*footbrake;
             }
             else if (footbrake > 0)
             {
                 m_WheelColliders[i].brakeTorque = 0f;
                 m_WheelColliders[i].motorTorque = -m_ReverseTorque*footbrake;
             }
         }
     }


     // this is used to add more grip in relation to speed
     private void AddDownForce()
     {
         for (int i = 0; i < 4; i++) {
             if (m_WheelColliders[i].isGrounded){
             m_WheelColliders [0].attachedRigidbody.AddForce (-transform.up * m_Downforce *
                 m_WheelColliders [0].attachedRigidbody.velocity.magnitude);
             }
             else
             {
                 if (m_WheelColliders[i].isGrounded){
                     m_WheelColliders [0].attachedRigidbody.AddForce (-transform.up * 0f *
                                                                      m_WheelColliders [0].attachedRigidbody.velocity.magnitude);
                 }
             }
         }
         }
 }

}