We've seen companies take a few stabs at smartphone-savvy heads-up displays for cars, but they tend to be one-way devices -- while they'll feed you info, you still have to reach for your phone to answer a message or get directions. Navdy may just have a smarter solution in store. Its namesake HUD not only projects car stats, navigation and notifications, but lets you interact with them through a blend of gestures and speech. You swipe with your fingers to either respond to or dismiss any alert that comes in; the system leans on the built-in voice commands from Android and iOS, so you can tell Navdy to get directions in Google Maps or play iTunes music as if you were speaking to the phone itself.