I'm not hoping to resolve the problem as soon as it exist since a long time among different models an I know how Sony dislikes to admit the fails.
What I figured out after some short research.
The car audio connection for the phone (don't mess it with media profiles!) is standardized as HFP: Hands Free Profile.
This essentially suppose an audiocodec called mSBC: an SBC codec with lower sample rate @ 16 kHz (and lower bitrate therefore).
Now, if you will go to the 'developer options' menu, you can find out (and supposedly change) some related options. So, you can find there (and force usage) the SBC codec.
But unfortunately, there is no option for getting 16 kHz sample rate (the lowest possible is 44.1 kHz).
Thus, those devices that strictly follow the standard (or jusl limited in recources) - shall not 'understand' what Sony streams to them.
Bravo, Sony engineers, very professional!
