I didn't have the nav in mine when i took it out, but in my jeep, i had a factory nav put in that i bought off of ebay, called the RB4. The updates for this are east-west disks, i wonder if they work, if i could find a trusty feller that would like to try em, they are fall of 06. thats about as new as they get, and i dont think they make em anymore. the features of that rb4 show similar info as the xf's.

Harman/Becker Automotive Sytems - RB4 - Dodge Ram

but for the sake of being logical, go out and by a garmin and spend the extra 100 to get lifetime updates