XM WX Satellite Weather General info
Garmin 478C at The GPS Store, Inc.
Link to the Garmin GPS Map 478 for $700 with turn by turn navigation and overlaid XM weather. And it will handle XM radio stations too.
XM radio is best for the long road trips when there are either no stations or that change every 15 minutes. When close to home, an Ipod / MP3 player works well.