Amazon.com: PyleUsa 8-Inch Low-Profile Amplified Subwoofer System - 600 Watt Compact Enclosed Active Underseat Car Audio Subwoofer with Built in Amp, Powered Car Subwoofer w/Low & High Level Inputs - SBA8A :
Amazon.com: Lanzar 6.5” Car Subwoofer Speaker - Black Non-Pressed Paper Cone, Aluminum Voice Coil, 4 Ohm Impedance, 600 Watt Power and Foam Edge Suspension for Vehicle Audio Stereo Sound System - MAXP64 : Electronics
Shallow subs for big bass in a tight space
Amazon.com: MTX TN8MS Terminator 8 Inch Micro Compact Amplified Subwoofer Enclosure for Small Vehicles with Class A/B Amplifier, Variable Bass Boost, External Bass Control, and Smart Engage Auto Turn On Circuitry :