Navman Smartst Software Anyone Recommend A Sat Nav With Good Northern Ireland Coverage?

Anyone recommend a sat nav with good Northern Ireland coverage? - navman smartst software

Hello, I live in Belfast and Northern Ireland to travel a little. I'm using with Navman SmartST software and it is terrible. It is the cities that use the roads. But from door to door residential areas is pathetic. Can anyone recommend a good market. Thank you very much.