Where should i begin... First off, if you're not looking for full out competition quality bass then you won't need more than one of these guys. I've got ONE 12'" P3 in the back of 00 Jeep WJ Limited and have to keep the sub turned down to -7 at normal gain on the amp. If not the sub just completely over powers every other speaker within a 100 ft radius. Keep in mind this will require a capacitor, extra battery or alternator to keep your headlights from becoming completely useless at night. To give you an idea of the power this thing packs it requires an 1200w max 600w rms amp to run just ONE. Anything less and its not hitting its full potential. I've only dared to turn it up all the way once in fear of the dreaded noise ordinance violations in my area and had a massage parlor on wheels. The vibes made my girl happy and i believe they'll make you happy to. stop listening to me and go get one!
Edit: Amazon.com has them for roughly $142
($107 off MSRP) as of 6/29/2015.