I'm not thinking that big. I'm just thinking of using a pair of free air 8" subs, and either putting them under the medical kit lid (ideal since it will hide the subs, however I wonder about the lid rattling), or I was thinking of trying to mount them directly under the rear headrests, as flush as possible. The rear headrests will still go down and rest on top of the sub's grills, and somewhat hide them, and then for max bass just raise the headrests. I wonder how thick the material is that the rear deck is made from (not the metal underneith). If it's 1/4 inch, the install might be fairly flush.... But right now I'd rather put them side by side under the first aid lid (they'll fit, I checked)
I don't need really loud bass, just good bass. Check these out:
Crutchfield 8" free airs Kickers
So with them side by side, do I wire them both mono, or stereo?