On stage at WWDC today, Apple's Craig Federighi announced a few big new features for CarPlay. First up, cars can now use different display sizes and high-DPI screens — good news for the look and feel — but more importantly, it'll now support apps from automakers that allow you to control car features through CarPlay. In other words, you won't need to leave the CarPlay interface to, say, change the radio or climate control — as long as automakers play ball and create the necessary apps.
Federighi also mentioned a wireless mode for CarPlay — you don't need to plug in your phone once you get into the car — although that was actually added in iOS 8.3. No cars currently support wireless mode, regardless, so it'll be something for the future.