Just FYI - The Nav update is pretty fool proof.
Meaning you can pull the CD or USB out (even in the middle of copying), and it will resume from the last file copied when it is reinserted. They did a good job of keeping it going even when you'd think you're going to mess something up.
I highly suggest that those who do the update do it while they are driving somewhere. This will ensure that the ignition does not turn off and that the battery is not unnecessarily drained. In accessory mode, it will shut off and stop the update after a predefined period of time. This wont happen with the ignition on, but that's a higher drain on the battery.
Take a trip and let it update on the way for best results - that way you get the update, minimize risk of delays from terminal shutdowns, and get to make headway to your destination all at the same time. Three birds with one stone
