Before you start driving, at stop lights, while waiting in lines, etc.
I don't know how it works on CarPlay but when I turn my car on I have a bunch of suggested addresses (home, work, parents, recent Maps searches, etc) that I just touch-to-go. Having to use voice every time you want to navigate not only sounds unnecessary, but cumbersome.
I purchased an iPhone 15 a few months ago and ended up making this discovery myself. CarPlay would refuse to launch unless I enabled Siri. I didn't do any of the Siri setup, or anything but the app would hard refuse to launch unless I went and toggled on Siri. Maybe that's different depending on your make/model, or the specific infotainment system in your car, but in my '21 Kia Forte, Siri is a very hard requirement.
You don’t need to enable Gemini or voice assistant on android to use android auto. Some functionality is lost, of course, but you can still navigate and play music.
I don't know how it works on CarPlay but when I turn my car on I have a bunch of suggested addresses (home, work, parents, recent Maps searches, etc) that I just touch-to-go. Having to use voice every time you want to navigate not only sounds unnecessary, but cumbersome.