Out of interest I've been looking at this on mine, so I have a 2016.5 (66 plate) NP300 and the SD card is a Nissan Connect 3 Europe V2 Part No. T1000-25802. The latest 2020 version is V5 and Nissan quote £109 for this. I note that if your vehicle is under 3 yrs old then it should be covered by Nissan MapCare so updates within this period are free .... wish I had known this before. Have a look at this link
Nissan | Navigation System GPS Map Update Home
It also looks like as the maps are stored on SD card there is no other way to update other than replacing the SD card, certainly not on mine anyway. Some other Nissans it would appear that you can download the updates, transfer to USB and then update your Infotainment system via a menu option.
Had a quick Google and there seems to be plenty of places selling genuine Nissan V5 cards for around £35 ... no idea how if Nissan want £109 for the same thing, go figure.
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