Our main cars now have satnags built in. Before that, I used a TomTom Go 930; quite an old device, but it had two neat features. One is that it has an SD card slot, so I can load up whatever music of my own that I want; the other is that it has an FM transmitter, so the sounds are played via the car's radio, and thus via decent speakers, rather than a tinny little in-built speaker.
Regards,
Martin