Don't buy a box for your sub. Make 1 MDF is cheap as hell and if you buy a shallow mount sub (MTX TT65) you'll only lose half your trunk space. Take out some of the metal loops in your trunk tub and bolt from inside the box through your tub. Cost you 25 bucks and can't be stolen without destroying the whole thing. The mtx sub a mentioned above only needs .75 cubic ft. And runs 400rms but hits like thunder so that will save you money on buying an amp that isn't a gillion watts.