Alpine - SPC-300A3 Premium Alpine Sound System for Audi A3, S3, RS3
Basser - FBaudi02 Audi A3 8P Fit-Box subwoofer enclosure
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
2017 Audi A3 Build Log | DIYMobileAudio.com Car Stereo Forum
Amplifier A3 AMP Induction Dynamics A3 Internal Class AB Subwoofer Amplifier | MSE Audio
BASSER Audi A3 8P - 8" Fit-Box Subwoofer Enclosure 8L
FBaudi01 Audi A3 8L Fit-Box subwoofer enclosure
American Bass Subwoofer Box FlagSeries | Sub Woofer with BOX | Croooober