I have a '94 Deville and I put one JL Audio 15 W0 in it powered by the rear channels of a 4 channel amp, giving the sub a mere 150 watts and it sounds really clean. i have my interiors and subs amplified well for a really nice sound and it didn't cost more than $500. the only problem is the box i designed to get such nice bass with such small power is a 6.0 cubic foot box and takes up quite a bit of space. if you're looking for loud bass, a ported box will be what you'd want. but if you're looking for tighter, not so loud bass, sealed would be better.