How can I get my car to stop moving?

Hello! I have a car script and I need to diable it (its a bus and once one 'ride' is over, it needs to stop at the starting point). Here is my code (comment where I tried to make it stop):

   using UnityEngine;
     using System.Collections;
     using System.Collections.Generic;
     
     public class CarEngine : MonoBehaviour
     {
     
         public Transform path;
         public float maxSteerAngle = 45f;
         public float turnSpeed = 5f;
         public WheelCollider wheelFL;
         public WheelCollider wheelFR;
         public WheelCollider wheelRL;
         public WheelCollider wheelRR;
         public float maxMotorTorque = 80f;
         public float maxBrakeTorque = 150f;
         public static float currentSpeed;
         public float maxSpeed = 100f;
         public Vector3 centerOfMass;
         public bool isBraking = false;
         public Texture2D textureNormal;
         public Texture2D textureBraking;
         public Renderer carRenderer;
         public CarEngine thisScript;
     
     
         private List<Transform> nodes;
         private int currectNode = 0;
         private float targetSteerAngle = 0;
     
         private void Start()
         {
             GetComponent<Rigidbody>().centerOfMass = centerOfMass;
             thisScript = GetComponent<CarEngine>();
             Transform[] pathTransforms = path.GetComponentsInChildren<Transform>();
             nodes = new List<Transform>();
     
             for (int i = 0; i < pathTransforms.Length; i++)
             {
                 if (pathTransforms[i] != path.transform)
                 {
                     nodes.Add(pathTransforms[i]);
                 }
             }
         }
     
         private void FixedUpdate()
         {
            
                 ApplySteer();
                 Drive();
                 CheckWaypointDistance();
                 Braking();
                 LerpToSteerAngle();
             
         }
     
     
         private void ApplySteer()
         {
             Vector3 relativeVector = transform.InverseTransformPoint(nodes[currectNode].position);
             float newSteer = (relativeVector.x / relativeVector.magnitude) * maxSteerAngle;
             targetSteerAngle = newSteer;
         }
     
         private void Drive()
         {
             currentSpeed = 2 * Mathf.PI * wheelFL.radius * wheelFL.rpm * 60 / 1000;
     
             if (currentSpeed < maxSpeed && !isBraking)
             {
                 wheelFL.motorTorque = maxMotorTorque;
                 wheelFR.motorTorque = maxMotorTorque;
             }
             else
             {
                 wheelFL.motorTorque = 0;
                 wheelFR.motorTorque = 0;
             }
         }
     
         private void CheckWaypointDistance()
         {
             int count = 0;
             if (Vector3.Distance(transform.position, nodes[currectNode].position) < 6f)
             {
                 if (currectNode == nodes.Count - 1)
                 {
                     currectNode = 0;
                     count++;
                 }
                 else
                 {
                     currectNode++;
                     count++;
                 }
             }
             if (count > 2 && currectNode ==1) //SHOULD BE STOPPING IT????????
             {
                 currectNode = 0;
                 isBraking = true;
                 currentSpeed = 0;
                 thisScript.enabled = false;
     
     
             }
         }
     
         private void Braking()
         {
             if (isBraking)
             {
                 carRenderer.material.mainTexture = textureBraking;
                 wheelRL.brakeTorque = maxBrakeTorque;
                 wheelRR.brakeTorque = maxBrakeTorque;
             }
             else
             {
                 carRenderer.material.mainTexture = textureNormal;
                 wheelRL.brakeTorque = 0;
                 wheelRR.brakeTorque = 0;
             }
         }
         private void LerpToSteerAngle()
         {
             wheelFL.steerAngle = Mathf.Lerp(wheelFL.steerAngle, targetSteerAngle, Time.deltaTime * turnSpeed);
             wheelFR.steerAngle = Mathf.Lerp(wheelFR.steerAngle, targetSteerAngle, Time.deltaTime * turnSpeed);
         }
     }