private void Start()
    {
        difVariables = GameObject.Find("DifficultyVariables").GetComponent <DifficultyVaraibles>();

        difVariables.SimpleCarSpawnCooldown = startSimpleCarCooldown;
        difVariables.HouseSpawnCooldown     = startHouseCooldown;
        difVariables.TruckSpawnCooldown     = startTruckCooldown;
        difVariables.CowSpawnCooldown       = startCowCooldown;
        difVariables.Building1SpawnCooldown = startBuilding1Cooldown;
        difVariables.FactorySpawnCooldown   = startFactoryCooldown;
    }
 void Awake()
 {
     if (DifficultyVariables == null)
     {
         DifficultyVariables = this;
         DontDestroyOnLoad(gameObject);
     }
     else
     {
         Destroy(gameObject);
     }
 }
    public Transform[] carSpawnPoints = new Transform[2];//0 should be left, 1 should be right

    // Start is called before the first frame update
    void Start()
    {
        OP                = ObjectPooler.Instance;
        DifVariables      = GameObject.Find("DifficultyVariables").GetComponent <DifficultyVaraibles>();
        carSpawnCooldown  = DifVariables.SimpleCarSpawnCooldown;
        houseCooldown     = DifVariables.HouseSpawnCooldown;
        truckCooldown     = DifVariables.TruckSpawnCooldown;
        cowCooldown       = DifVariables.CowSpawnCooldown;
        building1Cooldown = DifVariables.Building1SpawnCooldown;
        factoryCooldown   = DifVariables.FactorySpawnCooldown;

        StartCoroutine(StartSpawningSimpleCars());
        StartCoroutine(StartSpawningHouses());
        StartCoroutine(StartSpawningFactories());
        StartCoroutine(StartSpawningBulding1());
        StartCoroutine(StartSpawningTrucks());
        StartCoroutine(StartSpawningCows());
    }