In the right side rear of the wagon, there is a small panel that runs along the right side bottom of the wagon floor, it pops off and there is a weird drain hose that runs thru the body just past the rear wheel well. What is it for, the moonroof? Also, there is a weird vent, like a one-way vent, lets air out, not in, it is in the same location, more on the side though, what's that for, pressure release for when you close the doors/tailgate? Also there is a check valve here or is it a filter for the rear washer?