Hi Rich,
This is my first post here.
I found this useful information through Google. I am lazy so I just cut and paste :)
"I found a site that provides details on the version based on year of your vehicle:
http://www.sewellparts.net/Lexus_Nav_Generation_Chart.pdf
In addtion, there is also a link with detailed instructions on how to change the DVD software for the GX470 (as well as other vehicles)
http://www.lexus-parts.com/nav_install.pdf
The company Sewell parts sells the DVD upgrade for $299 less a special rebate of $40 till January 7, 2007 for a total of $259. The advantage over Ebay ... they quarantee the product will work with your vehicle with a warranty.
Ordering information ......
http://www.lexus-parts.com/partdetail.asp?...%20Notes:"
