Here is a ported enclosure I made to factory recommended spec for a pair of JL Audio 10w6v3 10" subwoofers. . The one pictured is about 1.5 cubic feet after all displacements and features a center port tuned to 39hz which takes up more displacement but also doubles as a brace. I can make these specifically to whatever size and tuning that you or your subwoofers desire. Just let me know what you want it to sound like. This ad and price point is for the center port style shown. 

This enclosure is ported, meaning that it has a specially designed air chamber to vent the internal air with the external airspace when the subwoofer is playing. This adds an increase in sound output near the ported frequency, and it is adjustable and tunable before the enclosure is built.

I have designed the enclosure pictured with a carefully calculated airspace of 1.5 cubic feet after displacement, and tuning frequency of 39hz to give a 10" subwoofer a great boost in the low end frequencies that it normally would not get when using a sealed enclosure, but without sacrificing too much trunk space.

Please provide the following information when you order. This will need to be the maximum allowable space that the enclosure can take up. I will do my best to make it as close as possible given the space requirements. 
Subwoofer Model: needed for cutout diameter and depth of magnet
Width: maximum allowable width
Height: maximum height
Depth: maximum allowable depth
Port: please choose frequency 

I make enclosures with several different options. Being that thes are usually made to order, I can add any details you would like. I have put the most common options in the drop down menus. 

Carpet: Charcoal Gray
                Black Carpet

Baffle:  Single
                Countersunk $25

Terminal Plates: Included and prewired

Materials:  Baltic Birch (not pictured but required for cost of shipping)

If you have any other special requests or ideas for me then please feel free to contact me for a free quote!