Aug 13, 2012 ยท Audi S4/A4/A4 Cab (B7 Chassis) . A4 Cab Subwoofer Install ... A4 Cab Subwoofer Install. Thread starter Joe_Murphy21187; Start date Aug 13, 2012; Joe_Murphy21187 S-Tronic.. "/>Audi a4 b7 subwoofer install