I have a 2009 which doesn't have A2DP, so I do have an iPod Touch gen 1 in the car, it works great, but I would rather just stream BT from my iPhone, it's always up to date and with me. So, I ordered this today, should be here next week. Only shipping option was SLOW.
This device emulates an iPod/iDevice and to the car interface appears to be an iPod but, it's a BT receiver for A2DP only. It has AVRCP and sends Metadata to the head unit just like an iPod. Supposedly you can remain Hands Free paired to the Navi head unit and this will pair to your iPhone as an A2DP device separately.
I'll test and report!
Amazon.com: ViseeO Tune2air WMA1000: Cell Phones & Accessories