One solution that has been tested in some forums for ViaMichelin X930,950,960,970,980 to get Tom Tom working from sd[Only registered and activated users can see links. ] The kit (17.5 MB) contains the files (shell included) to be installed on an SD card (Fat32 ,not SDHC) and the instructions.
-Insert the SD into the Navigator
-Press the key "Reset" on the back and wait until the launch of TomTom
Add a TT map and activate it.

A screen of files configuration
PVkk2ML
credits: olman