We’ve used the Amazon firestick before and it worked well. Currently we use the google chromecast/tv dongle for both ours tvs.

Nice thing about the google one is that it makes any Google movie/tv show purchases available, and Amazon movie purchases are still available through the Amazon video app.

But they’re pretty comparable. Depends mostly on what ecosystem you’re in or would prefer to be in.

Not sure what phone os you use but some of what you’re describing is built into iOS’s “drive” focus. And it can automatically turn on when your phone connects to your car’s Bluetooth. I’ve been using it for years now.

I’ve had my Roku disconnected from the Internet for a while now. I used to use an Amazon Fire stick, and currently use a Google chromecast