Enter/Exit Vehicle in 2D top down view

Hello I am trying to make a game similar to gta 1 or 2 .. where you have top down view and you can drive any vehicle.... but I ran in to a problem...

I made a script for entering or exiting vehicle.. script is attached to vehicle. And Vehicle (in this case tractor) has 2 colliders, 1 is for rigidbody and other is for player entering car, which is trigger. Problem is that camera doesn't get to 0,0,-10 everytime.. and when you press E it enters/exits several times, Here is my script:

 public int movementSpeed = 2;
 public int rotationSpeed = 50;
 static float angle = 0;
 
 GameObject camera1;
 GameObject player;
 GameObject tractor1;
 bool isInVehicle;
 bool isInCollider;
 Vector3 tractorPosition;
 //private Vector3 pos;
 
 void Start () {
     isInVehicle = false;
 }
 
 void Update () {
     if (isInVehicle) {
         if (Input.GetKey (KeyCode.W)) {
             transform.Translate (Vector3.up * movementSpeed * Time.deltaTime); 
         }
         if (Input.GetKey (KeyCode.S)) {
             transform.Translate (Vector3.down * movementSpeed * Time.deltaTime);
         }        
         if (Input.GetKey (KeyCode.A)) {
             angle = angle + rotationSpeed * Time.deltaTime;
         }    
         if (Input.GetKey (KeyCode.D)) {
             angle = angle - rotationSpeed * Time.deltaTime;
         }    
         transform.rotation = Quaternion.Euler (new Vector3 (0f, 0f, angle));
     }
     if (Input.GetKey (KeyCode.Escape)) {
         Application.LoadLevel(0);
     }
     if (Input.GetKey (KeyCode.E)) {
         if (isInCollider) {
             Debug.Log ("Key pressed...");
             camera1 = GameObject.FindWithTag ("MainCamera");
             player = GameObject.FindWithTag ("player");
             tractor1 = GameObject.FindWithTag ("tractor1");
             tractorPosition = transform.position;
             if (!isInVehicle) {
                 Debug.Log ("Entered vehicle..");
                 camera1.transform.parent = tractor1.transform;
                 player.GetComponent<Renderer> ().enabled = false;
                 isInVehicle = true;
             } else {
                 Debug.Log ("In vehicle....");
                 if (isInVehicle) {
                     Debug.Log ("Exited vehicle....");
                     camera1.transform.parent = player.transform;
                     player.GetComponent<Renderer> ().enabled = true;
                     player.transform.position = tractorPosition;
                     isInVehicle = false;
                 }
             }
             camera1.transform.position = new Vector3 (0f, 0f, -10f);
             camera1.transform.rotation = Quaternion.Euler (new Vector3 (0f, 0f, angle));
         }
     }
 }
 
 void OnTriggerStay2D(Collider2D col) {
     Debug.Log("Trigger entered....");
     isInCollider = true;        
 }

If you have any questions,, please ask. Thanks in advance!