BT on my 06 is sub par too. I get a lot of "I couldn't make out what you are saying" and "errgh, what?"

I found out that the louder I talk and the more I project my voice towards the mic, then the less complaints I hear.

 

BINGO, the mic should be on the side of that part of the headliner facing the driver. Most other cars have it that way.

 

Yeah, same with mine too, I can't talk normally. I have to raise my voice a bit for the other end to hear me.