Using MIUI, my car cannot access my phone's phonebook. I don't even get a message in the phone saying that the car is requestins access to phonebook.
Using stock samsung firmware (which I hate) fixes this.
Actually, the bluetooth works with my car system. I am able to make phone calls perfectly but just don't have access to the phone's phonebook.
This means that I will have to pick up the phone, go to my Contacts and place the call through the phone; I can then have the conversion perfectly through the bluetooth's audio.
On the side note, I have a bluetooth speaker (jambox) and also works perfectly.