Heres what i have to work with:
-I have 3, 8 inch DD1508 subs.
-2007 4DR Honda Civic
-The trunk is 45.5 inchs wide, and 36inchs in depth.

Any ideas , would be helpful

 

45.5" at the widest point? or between the shock towers?
Most SUV's have around 45inches or width.

Measure between the shock towers for width
Measure between the floor and rear deck/trunk springs for height (Or the trunk opening)
Measure from the bottom of the back seat to about 1/2 way to the trunk opening for depth. (This will allow you to still have room)

 

45.5 between the shock towers.

 

Nice.
Are you looking to have someone design a box, and you build it?
Are you looking to have someone design and build the box for you?
Are you just looking for some ideas on want to do?

 

well i would like some ideas and maybe someone desgin it , and i have someone that can build it.

 

DDAudio Digital Designs Speakers Made in the USA

^^^^^^^^^^ link to 3 subs and ported box volume.

Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators

^^^^^^^^^^ link to sub box building calculator.

Take the time and learn it for yourself. If you can use a tape measure and read, then you can use these links.

 

Took me about 15minutes to get this all worked out and drawn up
3.15ft^3 @ 36Hz