“OK Google” hotword detection is a staple of many people’s driving routine. Not having to touch your phone to perform actions is a great way to use your phone (in a strictly responsible fashion, preferably) in a safer way.
Strangely, Android Auto didn’t have support and you’d have to press the microphone icon to speak to it. Thankfully, a new update fixes that, adding support for the “OK Google” hotword. Now you can perform many actions without taking your hands off the wheel (and shifter if you’re cool) and without taking your eyes off the road.