box design help for DD3518g
 

if anyone can help its greatly appreciated
space im working with is
38"width
26"length
max height 36"
its a chevy trailblazer
amp is a hifonics 3200
all 0 guage wire
2 kinetic hc2400 batteries in back

i would build a 7.5 cu ft at 35hz (without calculating volume of the port)