Focal IBus 20 20cm Under Seat Active Subwoofer, 8" Active Bass Tube : Amazon.co.uk: Electronics & Photo
Active Subwoofer 15" Powered PA Sub Bass Speaker Low Pass Built-in Amp DJ 600W | eBay
8'' Car Underseat Slim Amplifier Subwoofer Audio Amp Sub Bass Box Speaker 600W | eBay
Monitor XT12 Subwoofer - 100W 12" Woofer | Polk Audio UK
BassPro SL | Powered, 8" (200mm) car audio under seat woofer system
Product Spotlight: Audiofrog GB Subwoofers
JBL BassPro Nano Ultra-Compact Active Under Seat Subwoofer Car Set 6" x 8" - 200 Watt Active Underseat Car Subwoofer : Amazon.co.uk: Electronics & Photo
EDGE 15 INCH SUBWOOFER 3200 WATTS CAR AUDIO BASS SPEAKER EDS15D2-E0 SALE | eBay
JBL BASS PRO LITE - Ultra-Compact Underseat Subwoofer Super Bass 200W | eBay
Infinity BassLink SM 2 8" compact powered under-seat subwoofer enclosure at Crutchfield