I found out the hard way CarPlay supports displays that are not touchscreens. The built-in infotainment system on this Audi A4 rental is controlled by a clickwheel of sorts down in the center console near the cupholders. The screen itself does not support touch, kinda like a TV.
And speaking of TV, navigating the CarPlay-compatible apps on your iOS device is somewhat like using the AppleTV remote, but worse. Unlike a TV, the device is very much in arm’s reach, so your impulse is to tap, swipe and pinch all the time.
I find myself wondering how iOS developers support scenarios where touch is not available; VoiceOver is my best guess. Also, there’s not much consistency in the aspect ratios of these screens, but I think developers are already dealing with that somehow (to support different sizes and shapes of iPhones and iPads).