From the horse’s mouth
They have achieved this through “Terminal Mode” which uses a “gateway app” installed on the phone and the phone linked to the system through a USB cable or a Bluetooth link. The phone’s apps can benefit from the larger display found in high-end car-audio installations.
The reasons I am pleased about this technology is that
a) the mobile phone that links with a car stereo for full functionality doesn’t have to be the Apple iPhone
b) there is an incentive for vehicle builders, car-audio manufacturers and handset manufacturers to establish a level playing field for achieving full functionality for mobile phones from the dashboard.
This can also lead to further functionality like Pandora, Last.fm, Internet radio, location-based services and extended navigation becoming available at the dashboard without needing to use multiple applications installed in a phone platform that you don’t have or on your car’s infotatiment platform.