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
Installed Helix Soundbox while keeping spare tire : r/GolfGTI
Helix Audio Upgrade Fitted - REALLY IMPRESSED - Modifying your Golf R MK7 - VWROC - VW R Owners Club
Helix Sound Upgrade | Stealth GTI
Helix soundbox! | GOLFMK7 - VW GTI MKVII Forum / VW Golf R Forum / VW Golf MKVII Forum
VW Helix Sub-woofer, Car Accessories, Electronics & Lights on Carousell
fender and helix sub | GOLFMK7 - VW GTI MKVII Forum / VW Golf R Forum / VW Golf MKVII Forum