Just wanted to clear up an possible misconceptions about our products. The BSW kit DOES make a significant, positive difference in sound quality and audio system performance. We do guarantee the performance of our systems, so if you're not happy, you can return them for a full refund. Here are links to a couple of satisified customers from this very forum:
http://www.xoutpost.com/x5-e53-forum/...?highlight=bsw
http://www.xoutpost.com/stereo-system...?highlight=bsw
Also, we do have replacement midranges specific to the X5:
http://www.bavariansoundwerks.com/product.php/II=489