We need to leave our suitcases in the car when we visit the Dam as we will be en route from GC to Vegas. Is it safe to leave cases in the car? Does anyone know if the parking lots are patrolled? We need to hand our hire car in when we get to Vegas and anyway only have a couple of days there so won't want to take time out once we arrive. Had our stuff stolen from our car years ago and it's something you don't forget. We won't be able to conceal it all. Thanks.