Car wont drive again after red light

I'm trying to make a red light green light game and i made a couple of very basic scripts that make a car drive forward then stop if light is red.

This is my light script

 var ligght = false;
 var target = Car;
 
 
 
 function Update() {
     if(Input.GetMouseButtonDown(0))
     ligght = true;
     
     if(Input.GetMouseButtonDown(1))
     ligght = false;
     
     }
 
     function OnTriggerEnter(other : Collider){
       if(ligght == false){
       
       target.speed = 0;
 
       }
       if(ligght == true){
       
       target.speed == 60;
       }
     }

This is my car script

 #pragma strict
 static var speed = 50;
 var crash = false;
 
 function Start (){ 
 rigidbody.collisionDetectionMode = CollisionDetectionMode.ContinuousDynamic;
 }
 
 function Update (){ 
 
 transform.position.z += speed * Time.deltaTime;
 
 if(crash == true){
   speed -= Time.deltaTime;
   }
   
   
 }
 
 function OnTriggerEnter(other : Collider){
    if(other.gameObject.name == "CarX"){
    crash = true;
    }
  
 }

Can you guys find the problem?