What's currently good for our ///M's? I've never gotten into sound systems and don't know where to start. Like many, I enjoy listening to music on a great stereo. M-audio came with mine; In comparison to the E60's Logic-7, it stinks... I would love to enhance the sound in a stealth way. I just barely have enough room in the trunk for luggage, with the subwoofers robbing space, and most certainly don't want anything bulky. The use of the fold-down seats is a must. Alpine, JBL, and BSW are a few I've seen online. What do you all suggest as far as quality and reliability?