I'm sure it works for some people, just relating my poor experience with it (only tried it once). Mostly surprised at how a significantly cheaper car can have a system that worked so much better out-of-the-box.
I cannot get the media voice commands to work on my iPhone 4S connected via Bluetooth. It just keeps saying the selected voice command is not compatible with your media device. I am able to use the voice nav commands and phone commands though. Has anyone else had this problem? I don't know if it's because I'm in Canada and we don't have entune up here...?
I haven't set up entune so I don't think you need it to use the voice commands. That said, I believe that Bluetooth audio streams wirelessly and is limited to just next/previous track controls. In order for the voice commands to work the stereo needs to have direct access to the player's library (or file structure) which doesn't happen over Bluetooth. If you plug the iPhone in you should be able to use the voice commands to control it.
