That works well I suppose if you're always using the same car. However, I go through a lot of rentals for work.
With a direct Android Auto status I could avoid having to setup a specific Bluetooth name trigger every time I use a new car.
I got it to trigger with Application Launched but for some reason Application Closed doesn't work for Android Auto, probably because of app not closing but going to background.
Same goes for detecting notification text, it triggers when "connected" text shows up but it doesn't when it clears.