I have an 07 rx400H. My Nav system is ver 6.1. I'd like to see if an upgrade to ver 7.1 or 8.1 might be worth the cost. I remember a post some time ago which explained how to view information on the newest Nav version. It was in the "My Lexus" area of the Lexus web site, I think. Can anyone tell me how to access the info pertaining to the latest Nav system upgrade? If I could preview the map info it would help me decide whether or not the upgrade DVD is worth getting.