Im still new here i think i have this in the right place, but yesterday i had my back seat out and i moved the carpet towards the front of the seat and i noticed i could see the ground. This was on the passenger side almost center of the passenger seat toward the front of where the back seat sits, then i turned around and noticed another hole on the driver side same spot, theyre not rusted through. My question is, is that hole supposed to be open or is there supposed to be a plug in it. It is noisier when riding in the back seat compared to in the front.