Siri's Eyes Free setting reduces driver distraction by keeping the iPhone screen from lighting up when the vehicle is in motion.
Siri requires Internet access and is available on iPhone 4S, 5, 5c and 5s; third- and fourth-generation iPads; iPad mini; and the fifth-generation iPod touch.
GM is not the only automaker to offer Siri software. Honda offers it as a dealer-installed option on its 2013 Accord and Acura RDX and ILX. Other automakers that plan to offer Siri include BMW, Mercedes-Benz, Toyota, Audi, Chrysler and Jaguar Land Rover.