In my spare wheel well is just a spare wheel! I queried the absence of the sub-woofer with the salesman at handover and he looked at me quizzically and said "It doesn't have one". He said the Audi Sound System just means additional speakers around the cabin. I've yet to put the sound system to the test. In the 2 days I've had the car my wife has been with me each time I've driven it and she doesn't appreciate loud music in confined spaces.