It seems like the concensus is that the head unit is the main reason the sound quality is lacking, even with the BOSE sound system upgrade. I'm wondering what others have done, aside from replacing the head unit, to get better sound in their W203's. I'd rather keep the steering wheel functionality of the stock head unit, and don't want to pay for the Comand at this time. My main gripe is the lack of bass, but I don't want to take up precious trunk space by adding subs in there like I did in my last car. Is it possible to put a subwoofer under the backseat and get good sound from it? I don't imagine there's much room under the backseat. Any personal experiences, good or bad, that members could share would be greatly appreciated.