1. Upgrade navi soft up to v27 or higher (v31-32 is the latest, more preferrable)
2. Enter to the Service menu (MENU->Settings->shortly press and hold MENU button approx 8 sec->Service menu will come on the screen)
3. Scroll down to the end of the screen and then one more click down-> you'll see Perspective menu->push on it and switch it on
4. Enter to the Navigation and switch on the map.
5. Press right button->you'll see Map positioning items and Perspective mode within them->switch it on
6. Enjoy the perspective view

Good luck!