I just purchased a 2008 Nissan Rogue which had the Nissan Portable Navigation System as a factory installed accessory. The GPS system is really a Garmin Nuvi 750, but the software has been modified for sale as a Nissan accessory. When the system is turned on, its says Nissan Portable Navigation. It also has an additional menu item to find the closest Nissan or Infiniti dealership. More info on the system can be found at:
http://www.garmin.com/nissan
The GPS system is hardwired into the vehicle's power supply According to a Garmin representative, the optional traffic receiver accessory (FM or MSN Direct) can be used with the system, but you cannot mount it to the Nissan installed mounting unit because the traffic receiver has to have access to the mounting unit for power (which it does not on the Nissan factory installed mounting unit). The traffic receivers have an integrated 12 volt power cord that plugs into the cigarette lighter. The other end connects to a mounting unit. The Garmin rep. said that I would have to purchase another mounting unit (windshield or dashboard) to use with a traffic receiver and plug the power into the cigarette lighter. Therefore, the Nissan Portable Navigation system is not very useful if would like to use the traffic feature on the Garmin. It would be better to buy a Garmin 760 or 780 with the traffic capability and a dashboard mount.
I didn't really need or want the Portable Navigation system, but it was already added at the factory on the vehicle I wanted based on its features and color.