Best way to replace a factory subwoofer? Buy one from me! I'll sell you this gentlly used woofer with a built in amp for $50+shipping. I had it under the back seat of my silverado for a year before I sold it and it's been sitting in a plastic bag in my garage since last Jan. Kicks a lot because of the low profile enclosure. Conveniently fits under or behind your seats. Just needs a power kit to hook up to your battery. PM me if interested.

http://www.crutchfield.com/p_777B8PT...ce-B-8PTD.html