M235i F22 underseat subwoofer upgrade - 2Addicts | BMW 2-Series forum
Genuine BMW - 65139210147 - Underseat Subwoofer - Left (65-13-9-210-147)
Genuine BMW - 65139210148 - Underseat Subwoofer - Right (65-13-9-210-148)
STEG BM8II Premium 200mm underseat subwoofer pair for BMW and MINI – DM Sound – Audiophile Speaker
Pics of Premium HiFi underseat subwoofers. - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
Underseat Woofer for BMW 3-Series [F30 & E90]
MATCH UP W8BMW-S Two 8" shallow-mount component subwoofers — designed to fit select BMW vehicles with under-seat subs at Crutchfield
Bavsound Ghost Underseat Subwoofer For E90/91/92/93 3-Series BMW (Pair – Dynavin North America