In conjucntion with the mobile device app (I use the Iphone version) it works well. You program where you want to go and it gets the route for you. Then when you connect with Sync it downloads it to your car. OVerall it's a pretty cool system.
Although I have noticed that it's really using math to determine where you are. I don't know if the car itself has a GPS, but sometimes I get to a turn a lot sooner then it think I should. That seems to throw the system off a bit. But overall it does a good job for long distance trips.