Collision with Player and DoorTriggerLeft

As I can do that when "Player" collides with "DoorTriggerLeft" change the value of "isPlayerVisible" to "True"

look at the script, you can add to achieve that

 // Attach this script to the door trigger gameobject.
 // By default any driving/car/control component script in the inspector should start out at disabled
 // so it will not move as the Player is being controlled by you, the user.
 
 var car : Transform;
 var player : Transform;
 var exitPoint : Transform; // Place this empty gameobject next to the driver car door.
 var doorTriggerLeft : Transform;
 var PlayerCamera : Camera;
 var CarCamera : Camera; // By default the camera "component" for the car camera should be set to OFF first.
 var isPlayerVisible : boolean;
 
 
 function Update()
 {
 if (Input.GetKeyUp("f")&& isPlayerVisible) //Asign any key you want to enter/operate vehicle.
 {
 Debug.Log("Driving");
 // make player invisible and still standing
 player.gameObject.SetActiveRecursively(false);
 player.gameObject.active = false;
 // parent player to Exit Point
 player.parent = exitPoint.transform;
 player.transform.localPosition = Vector3(-1.5,0,0);
 // parent PlayerParent to car
 exitPoint.parent = car.transform;
 exitPoint.transform.localPosition = Vector3(-0.3,1.5,-0.65); //Driverside exit point, adjust accordingly per vehicle.
 // GameObject.Find("VehicleObjectName").GetComponent("DrivingScriptHere").enabled=true;
 GameObject.Find("Car").GetComponent("Car").enabled=true; //Enables the script component to operate Vehicle.
 PlayerCamera.enabled = false; //Disables the playerCamera
 CarCamera.enabled = true; //Enables the carCamera
 }
 else
 {
 if (Input.GetKeyUp("r")) //Asign any key you want to exit/park vehicle.
 {
 Debug.Log("Walking");
 // make character visible again
 player.gameObject.SetActiveRecursively(true);
 player.gameObject.active = true;
 // unparent player from everything
 player.transform.parent = null;
 // exitPoint.parent = doorTriggerLeft.transform;
 // parent Exit Point to car gameobject
 exitPoint.parent = car.transform;
 // GameObject.Find("VehicleObjectName").GetComponent("DrivingScriptHere").enabled=false;
 GameObject.Find("Car").GetComponent("Car").enabled=false; //Disables the script component to park Vehicle.
 PlayerCamera.enabled = true; //re-enables player camera
 CarCamera.enabled = false; //disables car camera
 
 }
 }
 }
 
 function OnTriggerEnter(Player : Collider)
 {
 Debug.Log("Trigger Enter");
 isPlayerVisible = true;
 }
 
 function OnTriggerExit(Player : Collider)
 {
 Debug.Log("Trigger Exit");
 isPlayerVisible = false;
 }