MMI 3G Plus - After market subwoofer installation - UpgradeMyAudi.net
Speaker installation kit compatible with Audi A1 A3 A5 TT side panel
Audi A3 - Custom Stealth Sub Install (Pictures Included) - AudiForums.com
AUDI A3 (8V) REAR SPEAKER UPGRADE ONLY... - SCR Distribution | Facebook
M.A.P Audio & Customs - Custom made fiberglass 8" subwoofer enclosure for an audi a3 8v. This was hand made with mdf rings and support braces. It was then fiberglass and covered
Speaker installation kit compatible with Audi A1 A3 A4 A5 A6 A7 A8 Q3
AUDI A3 8V 2013 - Install Subwoofer - YouTube
Audi A3 8V | How to remove original SUBWOOFER - YouTube