SL350 bluetooth audio or new unit?

[ash213]

Hi guys, just bought a 2012 SL350.

The head unit/audio system is the standard factory fitted. Audio sound isnt amazing, maps look a bit dated, and doesnt have bluetooth audio to connect to my phone (or i cant seem to work it out)

so is it possible to upgrade the firmware on this, so that I can control the audio from my phone or at least play what comes out of my phone on bluetooth?

If not, what are the options in terms of a new unit, an updated model?

Also, can the speakers be replaced etc? what are the options.

Any advice would be great,

thanks