Need help with a dual SA-12 Build

[Optimuscope]

Hi all! So I’m wanting to build a box for the trunk of my challenger. I have about

31 in wide
18 in deep

14 in tall 

 

to build my box and have it fit very nicely. I’ve been scratching my head the last 5 days trying to find a build close to this and just haven’t been able to. I’ve sketched up a design but everything I read online seems to contradict itself in terms of what I actually have in terms of space. 
 

im looking for a ported box tuned around 35hz if I can do that. Wanting to do a slot port back subs back. 
 

subs are SA-12 D2 REV3 

amp is B2 2500.1 which will be wired to 2 ohms

 

will pay someone for a design if I like it and it fits. 
 

thanks!