MTX TNP212DV Bass Package Includes TNE212DV ported enclosure (with two 12" subs) and TNA500D 500-watt mono amp at Crutchfield
MTX TNP212D2 Bass Package Dual 12" sealed enclosure with 250-watt mono amplifier at Crutchfield
Amazon.com: DS18 SB12A 12 Inches Shallow Subwoofer Enclosure with Built in Amplifier – Car Audio All in One Amplifier and Subwoofer Bass Package 700 Watts Power – Great Stealth Car Subwoofer in
DS18 Better Bass Package - Upgrade your BASS
Car Audio Deals - Subwoofer Package, Loaded Enclosure, Car Audio Bass Packages