If you would like one cheap, it's probably best to find a one on Amazon or eBay. Just remember that when buying off these sites to check out the users rating. You don't want to be ripped off now! Or if you don't like online shopping, just head to a local car dealership or electronics store.
You can read reviews about navteq gps systems on the following site: http://www.navteq.com/. They have great products.
NavTeq is a company that makes maps digitally. These maps are then used in GPS systems that go into vehicles. While it operates independently, NavTeq is a subsidiary company of Nokia.
Tom TOM Gps units use the NAVTEQ GPS maps.
YF International (China) GPS systems contain NAVTEQ maps. If you go to the NAVTEQ website to buy map updates, strangely YF International is not on the list of brands for which they offer map updates. Your best bet would be to visit NAVTEQ website (http://allthingsnav.navigation.com/) and contact customer support with your query.
GPS systems tell it's customer where to go. Hopefully, this GPS system is reliable in it's ability to know exactly where it's customer is and where exactly it is going.
Navteq was created in 1985.
The population of Navteq is 4,400.
Navteq's population is 2,009.
Navteq's motto is 'The map the world turns to for direction'.
I think till now that I am working on it, the best, most reliable (including reality check methods, such as slope intervals) is using a directly recorded map software from some big companies such as DeLorme, Navteq or Garmin where the data are fixed.
A digital map company
GPS receivers get latitude and longitude position information, and time, from a constellation of 24 satellites orbiting 11,500 miles above the planet. How it derives a latitude and longitude from those satellites is near magical and beyond the scope of this answer. For a GPS receiver to provide street location it has to have a database of street level maps converted to latitude and longitude. The database is usually stored in internal flash memory or, in some cases, on a flash memory card. The two biggest map providers for GPS manufacturers are Navteq and TeleAtlas. The Navteq maps are reputed to cover North America better and are used in the Garmin units. The TeleAtlas maps are considered more accurate for Europe and are used by the Dutch company that makes the TomTom units. Most GPS units can have their map database updated or replaced entirely.