Car Subwoofer: Active Car Spare Tire Subwoofer High power - Temu
Genuine Volkswagen Audi - 000051419B - Spare Tire Mount Subwoofer Retrofit Kit (000 051 419 B)
Amazon.com: Cerwin Vega 12 Inch 150W RMS 2 Ohm Active Subwoofer for Car Audio - Compact Spare Tire Sub with Bass Knob, PWM MOSFET Power, Thermal Protection - Ideal for 12" Subwoofers
JBL Stadium BassHub Passive sealed enclosure with 11" dual 4-ohm voice coil subwoofer — mounts to hub of spare tire at Crutchfield
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