Also this guy will make the corner box for a convertible. just send them a message
https://store.audiodesignscg.com/product/2015-2019-mustang-subwoofer-box/
Isn't that connected with the microphone setup for sound balance. I forget what the system is. If you look inside the box for map lights there is another one. If so many disconnect them for less feedback.
Edit: Active sound generator...
What shop in Az so I never go there? Haha. Just picked up my 2017 Vert w/PP. Just swapped in the FP tune and CAI along with Magnaflow competition. Just having issues with fitment at moment because of the brace on vert. Waiting to hear back from Magnaflow about replacement or other.
I'm not sure if you're on here anymore, but I just picked up a 2017 Vert and looking to do something like this. Any chance you have the measurements of the box? I also see you're local in AZ.