If you think that your car's navigation is even closely comparable to Android Auto, you are living in a bubble. Get the Moto G7 Play and see what you are missing. You will not believe how inferior built-in navigation is, and I don't care which one it is unless you are driving a Tesla and have built-in Google Maps. But, besides being able to find basically anything you throw at Android Auto and invoke the best navigation system available with live traffic, constant traffic updates, alternative routes with alternative arrival times at every intersections, etc., Google Assistant has so many other features that you never know you are missing unless you try them. It can answer so many questions; it can translate to foreign languages, it can give you weather anywhere in the world, it can give you stock prices, currency conversion, 15-minute news summary for the day, answer all kinds of questions your kids have in the back, play games with your kids, tell jokes, sing songs, play riddles, etc. And, you keep discovering new things it can do every day. It's a treasure trough of knowledge and entertainment.
My son studies French in a French immersion school. I set Google Assistant for both English and French, and my son interacts with Google Assistant in French while I drive him to school. It's so cool that he can invoke all these features in it in French and Google Assistant interacts with my son in French. Every time we have an argument about how to translate something to French, we ask Google Assistant in Android Auto. It's freaking unbelievable. I tried to replicate this experience with CarPlay, and even though it can do several of those things, they are on a much lower level, and most of these things it can't even do. There is nothing like being able to answer numerous questions that you kids throw at you with a push of a steering-wheel button, which Android Auto does amazingly well, and Siri mostly struggles and very rarely able to provide any answers of value. Besides all of that, Google Assistant can also control your smart home appliances from the car if you decide to migrate your phone from HomeKit to Google.
As for the fact that Motorola G7 Play may have some negative reviews, please understand that I intentionally bought one of the least expensive Android phones because all I'm using the phones for is Android Auto, which Motorola G7 Play handles amazingly well (no delay, no latency, no hesitation). The phone is permanently connected in the car, so it's left there with the interior temperatures climbing well above 100F (perhaps as high as 150F) when the car sits in the sun for a while. Yet, every time I handle that phone, I can't help but think what a nice piece of hardware it is.
Obviously, if I were buying an Android phone to be my personal smartphone, I would buy something more upscale, but I would still end up with 1/3 the price of iPhone Xs Plus for a similar quality and functionality. I don't mind paying more for nice things; in fact, my life credo is not to buy junk and pay more for things that are of superior quality and last longer. However, Android phones have become so nice for a fraction of the price that it makes no sense anymore to buy phones three-to-four times as expensive that provide a similar functionality.
We will keep our iPhones for a few more years, but I can see us switching to Android at that point not because I hate Apple (I don't) and not because I can't afford iPhones (I can), but because it makes no sense to spend thousands of dollars more for similar quality and functionality. By that time, we may also switch to non-Apple computers in our household after having been 100% Apple for over a decade. That is for the same reason - the price is no longer justifiable. The rumored 16" MacBook Pro will start at $3000, whereas you can buy an excellent analogous non-Apple computer made of premium materials and components for half the price. Even though I despise Windows, I may go back to Windows just because I disagree on principle with paying $3,000 for a laptop.
Apple must realize that charging over $1500 and up for a phone and over $3,000 for a decent-screen-size laptop are insane prices that a lot of Apple's customers are no longer willing to pay. Apple must start innovating again for it to become attractive for me in the same way that I got attracted to Apple's products a couple decades ago.