Kenwood Excelon KFC-XW1200F Shallow-mount 12" 4-ohm subwoofer at Crutchfield
Pioneer TS-A3000LS4 - 12" Shallow-Mount Subwoofer with 1,500 Watts Max. Power - Walmart.com
Kicker 43CVT122 CompVT 12 inch Shallow Mount Subwoofer - Single 2 Ohm
Amazon.com: DS18 PSW12.4S 12" Shallow Mount Subwoofer 1200 Watts Max Power 600 Watts RMS Single Voice Coil 4 OHMS Water Resistant - Best Sub for Tight Spaces in Car & Trucks - 1 Speaker : Electronics
Rockford Fosgate P3SD4-12 Punch Stage 3 shallow-mount 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Pioneer TS-SW3002S4 Shallow-mount 12" 4-ohm subwoofer - Stereo West Autotoys