I have the Garmin TOPO maps for the US. You could borrow those if you want. Can you download maps to your GPS unit? Do you have any pics of the StreetPilot? I have a hand held unit that I want to mount in the X but can't seem to find a good location where I can see it well. Is your StreetPilot hardwired into the X or does it use the 12V adapter?