This is the precision-cut subwoofer baffle. This is the top plate of the enclosure and the main surface that the subs mount to. | 
The openings were channeled with a rabbeting bit so that the future weather-strip seal would have clearance into the box. The enclosure was glued together and joined with countersunk drywall screws. The box mounting holes were marked with a Sharpie and then drilled and tapped. This is the main mounting point of the enclosure. | 
An oval opening was cut into the face of the box to provide ample room for the integration of the slot port. |
All of the box edges were routed with a radius bit and then belt-sanded smooth. | 
The enclosure was test fitted into the car to check for sub alignment and box symmetry with the rest of the interior. This is another test of the battery airflow and clearance. | 
To form the framework of the slot port 11/42" MDF was cut. This size was calculated to provide a tuning frequency of 31Hz. The pieces were joined together using superglue. |
The port's outer edges were rounded over to lessen airflow restriction within the enclosure. It's a good idea to round or make a radius on anything you plan on putting inside your enclosure. This includes bracing. | 
The oval shape I cut into the enclosure was traced onto MDF and another template was created with the port mouth opening cut in the center. | 
Rage Gold body filler was applied to the template to fill the gaps and to reinforce and seal the 90-degree bend in the slot port. |