Koopa is in the bathroom of the house, which is the entrance to his special warehouse. He rubs his shell against a special part of the bathroom tile wall, and it opens into a huge space. There is a small shack that Koopa sometimes sleeps in, and next to it a car, that got stuck in the warehouse and can't get out because the only way out is through this bathroom entrance. Wait, how did these things even get in, then?