Today at Google I/O 2014, Android Auto was announced as a means for drivers to access the full breadth of Android apps with total hands-free usage, though there's also a dash touchscreen interface. Obvious apps where this could come in helpful include GPS navigation, communication, and music.
Directions are spoken out loud as you progress towards your destination. Incoming messages are read out loud to you and show as heads-up notifications. The steering wheel voice button can be used to instantly reply. Your Android handset broadcasts the customized interface to the car display on the fly. The overview screen provides contextually relevent information from Google Now and other apps, all with the same fidelity and functionality of their mobile and web counterparts.
An SDK is being made available soon so developers can build out their own automotive apps. 40 brands have already signed up to use Android Auto.