ricko , your unit is running igo street navigation software and the off road is vms their own , and also ozi explorer.
if you go to the vms website you will find some software updates for your unit and also instructions on how to update maps and other info about your unit.
if you go to the igo section of this website you will find new maps for your street navigation and instructions on how to put them on your unit.
if you go to the ozi explorer part of this website you will find other maps to suit the off road part of the software and VMS has a map converter for free on their website. hope this helps even if only a little bit . cheers ewok.