According to my owners manual it says in order to use Pandora, you must have the app on your phone and the phone plugged in via USB. I already had it on my iPhone but I had to delete it and reinstall and when I plugged it in via USB it worked.
Launching Pandora
Connect the iPhone, iPad, or iPod
touch to the USB port, or connect
an Android or BlackBerry through
Bluetooth. See Auxiliary Devices on
page 40
or Bluetooth on page 71.
For first-time use, set up stations
before connecting to the vehicle.
The Pandora icon will be available
on the Home Page and the source
pop-up displays if the latest
application is installed on the device.