At the New York International Auto Show, Apple's CarPlay system was demonstrated in upcoming cars by Volvo, Mercedes-Benz, and Hyundai. In its current form, Siri becomes the lead mediator between your iPhone and the vehicle. Instead of the iPhone's mic, Siri listens to your voice via microphones built in the auto, and functions as an elaborate hands-free tool - it lets you call, text, listen to music and set travel routes.
Other than this basic mechanism, Apple has left it up to vehicle makers to decide how best to incorporate CarPlay in their products. Thus, Hyundai and Volvo drivers will be caressing touch-screen displays, while Mercedes-Benz is going the old-fashioned physical buttons route. Additionally, Volvo has decided to let CarPlay access and control the vehicle's facilities, such as climate control, while the other two treat it like an app that's supposed to be opened and closed depending on whether you use it. This doesn't sound very seamless.
Apart from the aforementioned manufacturers, only Ferrari and Honda will be launching CarPlay-enabled vehicles this year. But if you don't want to buy a brand-new luxury car, fret not, as Pioneer will be launching an aftermarket receiver that should fit in your current ride (and budget).
source: The Verge