I believe part of the reason for the openings was for the "Astro Flow Through Ventilation" that circulated air through the car and out the door jamb vents. Air flowed through the cabin into the trunk and out the vents. I saw your post a couple days ago but didn't respond because I'm not an audio guy and don't know how sealing it off will affect sound quality. I sealed mine off because my car is more of a track car and fire possibilities are more important.