I didn't know about this. In fact, I have no problems with bluetooth in my car. It's performing quite well, and I noticed a hughe improvement compared to MIUI V5 (the sound now is almost perfect, while on V5 was very difficult to be heard by the caller).
The only thing I complain about is just (let's say) a cosmetic issue, because I see numeric code in the bluetooth of the car instead of the name of the provider. And this is only affecting MIUI V6 (on MIUI V5 it worked correctly, and on Lollipop it's also correct).
I'm not so sure about the origin of the problem, as you mention.
You still didn't get it.
BT is not just a simple function. The interaction wit your car goes n several levels including, but not limited to:
- Sound transmission
- Access to contacts, and respective call logs
- Menage SMS
- Remote operation, for example, end and start calls
- Sound notifications
- Manage input/output sound, for example switching from car speakers to phone speaker, or mute mic, etc.
All the above worked flawlessly in V5 KK, but then they moved to V6 and afterwards to LP and we lost call logs, Dolby and BT stack