Not a new idea...
We visited my family-in-law in South Korea last year, and my brother-in-law had a TV-enabled satnav in his MPV. Koreans seem to like TV wherever they go - quite a few mobile phones over there have TV tuners, as do many subway trains in Seoul, for that matter.
Anyway, the TV-satnav helped pass a long car journey we went on during the visit, though I'm still not sure of the idea of a telly visible from the driver's seat (and surprised it's even legal in the UK - is it?).
Mine's the one with the insurance details and driving licence in the pocket (just in case...).