[blitzkriegoutlaw]

I have 2009 E89 and the sound doesn't get very loud, especially with the top down. Can I just replace the head unit and line up the wiring, or is there more to it? What do I lose if I replace the head unit (e.g., the ability to program the car or some units)?

VIN Decode
S645 BMW US Radio
S663 Radio BMW Professional
S693 Preparation BMW satellite radio
S697 Area-Code 1 for DVD
S6FL USB/audio interface
S639 Preparation f mobile phone cpl. USA/CDN

In the trunk there are two boxes on the left hand side (TCU 1.5 MOST GSM and I assume the phone bluetooth unit). There are no boxes on the right hand side where an amp normally goes. I don't pay for BMW assist or anything like that.

I've searched and BMW has so many combinations that the answer are not very straight forward. Thanks for your help!