I am selling a custom built fiberglass subwoofer enclosure with dark grey carpet, built to specs for a JL Audio 10w3v3 subwoofer. It is built to fit in the rear right corner cubby over the battery. I sold my 3 series f30 so I know longer can use this enclosure. It looks factory when installed and sounds amazing in the car. I'm selling for $350 shipped. Save space and have that custom look for your subwoofer integration. (JL sub not included, enclosure+shipping only)