Barry from Texas

I don't know about a direct software hack, but there is some hardware sold out of the U.S. that claims to unlock the Navigation and a whole lot more. They have different versions for each generation of the Lexus GPS System. Check them out at : <http://www.coastaletech.com/BLUE_lockpick1.htm> (And no, I have absolutely no connection with the company, I just happened to find them during a Google search on how to disable the Navigation Lock) Hope this helps