Siri eyes-free car integration
Apple teases Eyes Free, Siri car integration -- Engadget

From Apple WWDC Keynote:
"You've heard of hands free. Now its Eyes-free....Lets you keep hands on steering wheel while you're using your phone." Working with a number of car manufacturers to use a button on the steering wheel to trigger Siri.
A number of auto manufacturers have already committed to deliver eyes-free Siri integration in the next 12 months. BMW, GM, Mercedes, Land Rover, Jaguar, Audi, Toyota, Chysler, and Honda.