Okay, E46 320i, horrible business CD stock sound system, no CD changer. I'd like better sound but I'm poor, so I'd have to do it in pieces. I DON'T want a bass-bumpin machine. Rap NEVER stains my ears and I would kill anyone who even TRIED to play a rap CD in my car.

But I'd like better sound, QUALITY sound, not just volume. I listen to a lot of classical and ambient electronic shit that just sounds awful on a stock BMW system.
So, what do I do first? Right now I'm kinda dying for an MP3 headunit, preferably one that plays MP3s from DVD-R discs so I can skip the iPod bullshit. So I was leaning towards that first. Where can a car audio noob research speakers and head units? Anyone got any good links, advice, etc?
Bart