I have an A3 Sportback Sport with lots and lots of factory extras on it. (07 Plate) I was giving the car a good detail today and was vaccing out the boot with the stereo on. I stuck my head in the boot and the bass was really intense and seemed to be coming from the nearside panel in the boot area. I have the Symphony II+ stereo which is a 6 CD Changer (MP3) but none of the speakers have the little bose badges on them. Does anyone know if you have a sub, you must have BOSE or did Audi do a non BOSE system which came with a sub in the boot. I havent peeled off the panel yet as it looks a swine to remove, but there is definitely something back there. I must say it does sound pretty good, albeit the wife moans that it defeaning our little one !