Also note that in the purchase of car navigation systems, in addition to pay attention to the brand of the navigator car navigation map. Now many manufacturers of bmw dvd navigation GPS navigation map. Staff with GPS navigation GPS "get lost" mostly because of the use of pirated maps. It is understood that the general price of some well-known manufacturers of car GPS navigation systems are more expensive, but mostly with genuine map, a free upgrade to the new version of the map function. The prices are relatively cheap navigator, material, workmanship, etc. is not bad, because they do not map with genuine price will be more than a difference of thousands car gps dvd player.