I have a '03 X5 with no NAV, no DSP, no Cd changer. I have a budget of max $1500 to upgrade my audio system. I've been looking at the Bavarian Suondworkds speakers/sub package but somehow I don't feel it's adequate. I am not looking to build a loud system that my neighbor can hear. Just enough for good clean music. Can you guys recommend what I should replace and brands please?

Thanks.