Navigation disk

I bought a 2001 STS. LOVE it by the way. It is my first Cadillac and Im loving everytime I can drive. Anyways, I have a nav disk that is GM p/n: 25725891 Year on disk is 2000. Does anyone know where i can buy a updated disk and what would be the newest I can use in my car.
If you have to contact me send email to

put Cadillac nav in subject line.

This might be the site to look for your new disk: