Does anyone know the size of the cutout area for the factory sub location without the sub mounting panel?

I am not interested in using the factory sub mount panel (probably bad sound quality due to the flex of metal and the lack of good sealing.

I plan to build an mdf enclosure to fit in there with a metal panel attached that would screw into the factory location but I need to know the width and height of that hole so I can plan the box accordingly.