I was looking under the hood of my 2013 Nissan Quest (joke unintended) and noticed a funky box at the front of the engine on top of the radiator. It's a factory part, and it connects directly to the air box that has the filter in it. I wanted to take the beauty cover off, so I pulled it out.

Noticed that it has vents on the side closest to the air box, and the other side looks like it should have vents as well. However, the far side is completely closed off. Wondered how important this part is because it seems to block a lot of airflow to the engine compartment, but I could see how if it was gone, the airflow would come directly from the engine compartment instead of the outside of the car at the top of the grill.

Oh, and it looks like the Muranos had the exact same setup. Car is running fine, I just wanted that cover off. Probably best to leave it alone, but curious nonetheless.