03 S600 Audio and phone system question
 

Can anyone tell me if I can upgrade my audio system? I would like to get a system that will BT to my phone and have a GPS that works.

Yes you can , the Chinese android units that are plug n play for the w220 seem to be the best option , otherwise it is very difficult to integrate a regular alpine /pioneer/Kenwood unit wth the factory speakers and amps

Can you tell me what to and where to look for?

sure here is a very detailed thread on it
https://mbworld.org/forums/cl-class-w215/628129-head-unit-question.html

Thank you, but not real helpful. Has anybody taken a D2B system, with the 90 degree connector, and install a MOST connector on it? I would think the systems would work the same, just the connectors are different.