Amazon.com: Skar Audio Dual 12" Complete 2,400 Watt SDR Series Subwoofer Bass Package - Includes Loaded Enclosure with Amplifier : Electronics
2011 Volkswagen GTI custom subwoofer enclosure and speaker upgrade - Handcrafted Auto Marine & Offroad
For those of you who want more bass but don't want to sacrifice your spare tire or hatch space, I highly recommend this spare tire mount subwoofer : r/GolfGTI