With a 2005 you should have both Bluetooth and Assist in the vehicle. You do not need a cradle. In fact, there appears to be a wiring incompatibility with the 2005's that may preclude them from being able to use the cradle.
See
http://www.xoutpost.com/articles.php?...ticle&artid=16 for info on pairing a phone in the 2005