HDD in a JD car, what does it contain?

[mak]

In auction sheet translated by Japanese guy say it has HDD, Navi, TV.

I can understand TV and Navi, but what are the possibilities with HDD (I think it is an internal heard drive), does it store MP3, video and can play them?
Please help me those who from Japan/ who handle these media unit.

[inokiyo]

HDD Navi = Hard Disc Drive Navigation system.
The navigation system uses a CD with maps, details of the region in combination with GPS. It is usually useless in other countries unfortunately...

[mak]

Originally Posted by inokiyo

HDD Navi = Hard Disc Drive Navigation system.
The navigation system uses a CD with maps, details of the region in combination with GPS. It is usually useless in other countries unfortunately...

Thank for information