ALPHASONIK APP122 Complete 1500 Watts Dual 12" Subwoofers Car Bass Package with Amplifier and Installation Kit Included - 2 Sub Woofers with Grills in Custom Ported Box Loaded Enclosure, Black
Vibe Car Amplifier + Subwoofer + Speaker Upgrade Kit for BMW 5 Series F10 F11 | eBay
Amazon.com: Audiopipe APSB-1299PP Dual 12 Inch Car Audio Subwoofer Speakers and Sealed Enclosure, 2 Channel 500 Watt Amplifier, and Wire Installation Kit : Electronics