Has anyone installed one the BSW systems in their car or SAV? Am thinking about the Stage 1 for my 2005 X5 with DSP and factory installed subwoofer. Am also looking at replacing that with the Powered BSW subwoofer as well, but want some feedback before spending money on something I have never heard. The products look to be well made and the "plug & play" installation looks attractive as well. They have been advertisers in Roundel for years as well, so that gives them some credibility, and the lack of negative press speaks volumes as well. Thanks for any replies.