I'm not too concerned about people seeing the grille for a sub in that panel. A lot of suv's of all makes and sized have a sub in this location.

I do know that I will be cutting this panel for some kind of air movement. I drove around today with the cover in place and I can't say it sounded all that bad if you can tollerate a little rattle at times. But just 3 miles tonight with the cover removed convinced me to go ahead and get the door cut. Really it just sounds so much better with the sub being unrestricted.