file format for nav maps?

[wildcat_lgf]

I did a search but couldn't find what I need.

I have a stilo with sat nav, but there are no maps available for it here (overseas).

But, we do have an active gps forum which have produced maps etc of the country which I would be keen to see if I can get working with the standard sat nav system.

I know I should just buy a tom tom or garmin, but...can someone point me in the right direction regarding appropriate file formats required for the system, so that perhaps I can create my own maps that work with the system?

Any advise welcomed.

 

[hsnz]

same thing here, even the Blu&Me TomTom is not having any maps for my country. Is there any way to get around this ?