Still having these issues. Anyone else seem to get it? A quick browse in the One X forum shows that a couple of the users with that phone are having an identical issue. I imagine HTC use the same BT chip on both phones.
Phoned HTC and they were completely unhelpful (they told me to speak to Audi, who in turn told me to speak to HTC - I'm fairly sure its nothing wrong with the car, it never had this problem before).