This is going to have an interesting purpose in the audio system. There will be one on each side of the dash. They will open when the head unit is turned on and the midrange/tweeter pod will rise up through it. Then when the system is off the pods will return below the dash and they will close concealing the drivers.
So it turns out the fiat seats we put in the Grumman have heated cushions. Got the drivers seat wired up today to check. It works great. This is going to be sooooo much better on these cold days.