this is my story of installing the Garmin USA and MFM map on my iPhone...
I've downloaded Garmin USA and installed it as normal.

Then I followed guide from FaZo on Page 2 of this thread to copy the map in folder "var\mobile\Applications\[xxxxxxxxxxxx]\garmin-nav.app\storage-usa\.System".
Somehow when I reached folder "storage-usa", I cannot find folder ".System". I go to setting, and set "Hidden Files" to ON, and go back to the folder "storage-usa", and wholla, the folder now appears.

after paste the map in that folder, I tried to open the garmin usa apps and the authentication failure error comes out.
Following tips from phanghy, pos, klse82 and kaplex, I then edit "/etc/hosts" and insert the followings at bottom of line (open the "hosts" file by using Text Viewer) :
127.0.0.1 Garmin | United States | Home
127.0.0.1 gold.garmin.com


then I respring my iPhone (not sure needed or not, but I just do it) and tried to open garmin usa apps, it crash, tried it for another 3 times, and the third time, it work!


