Amazon.com: Massive Audio UFO12, 12 Inch Shallow Subwoofer - High Powered 600 Watt Shallow Mount Subwoofer, (3 Inch Voice Coil Dual 4 Ohm) Low Profile Car Subwoofer with Deep Bass. Sold Individually : Electronics
Alpine SWR-T12 Type-R Thin 12" 4-ohm shallow-mount subwoofer at Crutchfield
10' -12' -800/1000 Watts - Flat Shallow Mount Subwoofer (FSW-10, FWS-12) - China Subwoofer, Car Subwoofer | Made-in-China.com