if you got the money and you want lots of power check these subs out
http://www.incriminatoraudio.com/ look at the death penalty's. my buddy has to DP 15's in his truck and they straight destroy everything in sight. I'm talkin brokin dash, mirrors fallin off the truck, back glass shattering, and just straight up 1500watt rms continuous power. they can even do 2500watt rms burbs. oh yeah he does hair tricks.
as for as the 12's, there 1500watts rms too and they only require 2.5cuft per sub. so if you wanna do what i might do get two of them. a single chambered ported box with 2 DP's requires at lease 5cuft net and then box with port should come out to be around 7-8cuft gross and if you design it right it will fit our trunks
no thats just crazy power
but if cant afford that which i know i cant im buying 2 of my buddys massive audio DC12's
http://www.massiveaudio.com/st....html they are the next step up from what i got now and only 100watts more but the spl level is way higher and xmax is twice as much. TW's xmax is 24mm. DC's xmax is 40mm. thats a lot of air to move