Custom validation

hi i have a problem to validate is_unique with soft delete , i create a custom rule :

Code:

    /**
  * Funzione che controlla se è presente la macchina in magazzino
  */
    public function macchina_presente_is_unique(string $str,string $fields, array $data)
    {
        $macchina_model = new MacchinaModel();

        $macchina = $macchina_model->where('seriale',$data['seriale'])->first();

        if ($macchina) {

            return false;
        }else{

            return true;
        }

    }

There is a way to add a field to ignore id as is_unique {id}

PHP Code:

->withDeleted()->first(); 


PHP Code:

->withDeleted()->first(); 


No in this way Is the same as is_unique ... 

I want add a value tò control the id , i create another function , i want know of Is It possible do with only one function