i have tom tom if there is an easy way of sending it over the net, it's 250mb though but you will have to use an external gps receiver, i had a holox one and it was the bollox by the time totom has loaded on the phone i will usually have signal, might need a newer map if your in london it work's still but i have been taken to a couple of dead end's , but it changes so often it can't always be helped