You probably know that the iPhone every time you open the Maps application accesses the network and extorts that piece of the map that you need, on the one hand it’s good - you don’t need much space and a quick update, but with barbaric prices on GPRS \ 3G it’sn’t real, I suggest below little trick.

Note, the cards work in airplane mode, without WIFI
To access offline maps we need to have some kind of file manager for iPhone
under Windows, for example,
Winscp or
ifunbox (both are free), only winscp for access via wifi and ssh and ifunbox via cable
Now we need to take the cash cards of Moscow and put them in
MapTiles.sqlitedb copy to \ private \ var \ mobile \ Library \ Caches \ MapTiles \
For firmware 3.1 in private \ var \ mobile \ Library \ Caches \ Maps \ MapTiles \
com.apple.Maps.plist copy to \ private \ var \ mobile \ Library \ Preferences \
Copy
bookmarks.plist to private \ var \ mobile \ Library \ Maps \
it will also be good to change the rights to the copied files using iFile \ terminal \ ssh, but it is not mandatory
')
Cash Moscow as well as other cities can be downloaded from torrents, for example, a map of
Moscowor download via
MAGNETThis is what is included in the offline access map above.

You can also make your card using
this program.
I hope the instruction is useful to you, save on traffic!
PS You can also do it on your iPod so that you can watch maps without Wifi.