For Audi A3 8PA Subwoofer Housing 20 CM 8 Inch Woofer Space-Saving Boot 4047442079405 | eBay
Audi A3 - 8" Fit-Box Subwoofer Enclosure 8L
Alpine - SPC-300A3 Premium Alpine Sound System for Audi A3, S3, RS3
OEM Audi A3/s3 8v Sedan Loudspeaker Subwoofer 8V0035412B for sale online | eBay
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