^ To the left of the Power button (touch key) for the Infotainment system there is a pinhole push-button that can be pressed to either re-boot or reset the system. Pressing the button once reboots the system without losing any information; however, pressing it in for about 5 seconds does a full reset and you will lose all settings. You may to want to carry out a full reset of the system to see if your navigation and maps come back. If they don't, then a visit to the dealer is definitely recommended. Let us know how things go.
- Richard