I made my own custom box that fits between rear seats in my wagon....
Currently have some terrible 10" DUAL 300W subs. They just ****, but worked fine for a number of years when I didn't really need much bass.
Whats some good subs that will fit this box? Something under 300W RMS will be plenty fine. I don't need much power, just enough.
The inside has two separate sealed chambers for each 10" sub.
Odd shape I know....but it fits so, so perfectly. It allows my 3rd row of seats to be fully functional -- I made the box this dimension specifically for this, so not changing it. I know I should be able to get the bass I want from this size sealed box.