First off, there is no way (legally) to DIY the map update.
Secondly, Don't trust a salesman to give you information on something that would happen after the sale.
Most dealers do not update the map software before the car is sold no matter how long the car has sat on the lot. Check the version before buying one...
If you address of street is missing try contacting Navteq they make the software for all Nissans, and many other manufacturers for that matter, just look at their website.
http://www.navigation.com/is-bin/INTERS ... JE_7GhY2Iw?
A navigation system typically integrates gps capabilities with other functions typically in order to properly navigate a gps receiver is required. A navigation system usually encompasses add-ons like a maintenance calculator, and fuel economy monitors.
The facts are,
-A new navigation software edition is released every year, just like your portable unit
-Only the initial one is free
-Only the dealer can install a new software
- Installation is typically 1 hour labor
-When the purchase is completed the purchase receipt contains an 8 number code. The dealers consult III has a program that when connected to your car they generate a unique code that must be entered (along with a few other details) into a secure website (that can only be accessed through a Nissan dealer portal) to generate a third 12 digit alpha numeric code. There is allot actual work that needs to be done to complete this update and that does not include the time the software takes to update.
-The update is actually the exact same that you can purchase for your mobile device. If you have ever purchased new maps for one of those you know how long the software takes to load as the file size can be a few gigs depending on your OS.