The Garmin Head-up Display ($150) receives navigation information from your smartphone and projects it onto a transparent film on your windshield.
The device displays turn indicators, distance to the next turn, current speed and speed limit, and estimated time of arrival.
Place HUD onto your dashboard and pair it wirelessly with your compatible Bluetooth-enabled smartphone. Using Garmin StreetPilot for iPhone, choose your destination and HUD will project turn-by-turn directions to get you there.