If you are referring to Nissan's Birdview navigation system, then I'm afraid you are stuck with it and you'll just have to try and learn to love it. I had a TomTom on my previous car and, IMHO, it is far in advance of the Nissan system. The lack of post codes alone is a big loss, but other factors like not being able to download your favourite POIs, like speed cameras, supermarkets, campsites, etc. make it very much a poor relation. The only saving grace is the fact that it is built-in and, in theory, is reasonably theft-proof is one advantage.