I have an 09 with Nav and wanted the Bluetooth streaming audio experience as well. I also wanted to be able to control the media player and see the song metadata on the car's screen, just like if I had a iPod connected. I also wanted to use my Android phone as the media player.
Turns out that I had to build my own interface (which I just started working on again). It connects to the iPod interface cable and mimics an iPod (as far as the car is concerned) and relays commands and data to and from a connected Bluetooth device.
This is the only way I know of that you can play and control a Bluetooth device using the 2009's native controls. It just does not have any other mechanism for his.
Below is my current solution that I am using daily:
2009 370Z IPOD -> A2DP Bluetooth Unit