so i have "Enlarged map of the intersection" set to 3d - the book makes it sound like this automatically comes on when you get near an intersection but no matter what intersection i come to nothing happens... what am i not doing?

You have to have a route set. Pick a destination...

While you are en route to a destination, and a turn is coming up at an intersection, half of the screen will show you an enlarged image of that intersection with arrows guiding you from your travel path to where you need to turn.

This feature will only show you the picture of the intersection while a route is programmed.

Plus, it would be kind of annoying to have it pop up at every intersection...