I also own a 2007 GX470 and I can't even get as far as you've gotten. I can't seem to get the GX470 to recognize my Blackberry 8703e. Can you help with this? I would be so appreciative. Thanks.
What you need to do is first transfer your address book into a Singular / ATT phone and then from that phone it's a snap to tranfer your address book into your Lexus. It's a 2-step procedure, but it works real well. Good luck