Custom map /google maps to Prius navigation system?

Hi this is my 1st post and im from srilanka.
When u got a prius it is equipped with original Japanese navigation system ,which is in japans language and japans map.

So is there any way to add custome map or google map in to the navigation system with srilankan map.

 

thanks mate.

Yes i can remove the head unit, but it contain the auto parking facility so if i remove it, the autoparking will also going away rite?

 

badly it is not available for srilanka map.