I installed this in my 2006 scion XB. I removed the plastic tray in the back to the right of the spare tire. I cut out the bottom of the foamy/plastic tray and stuck some velcro to the bottom, Stuck some velcro to the top and attach the sub itself to it. The padding acts like a cheap dynamat. And I put the cover back over it, cut a hole out for a speaker grate. It all looks very factory and the sound is great.
If you are looking for 2 12s, then get two twelves, These wont run in the same field but honestly they sound and bump great. I dont care if everyone else hears my music, just me, and for that case wow it sounds great. The price just cannot be beat if you want a cheap way to upgrade a factory radio just a bit.
Small size makes it easy to hide as well.