Yes! Many major brands have been steadily adding AA as a standard feature, and more brands are coming on-board as we speak. Please integrate with it! Maybe release a separate paid "add-on" applet, "Poweramp for Android Auto", so that you don't "impose" it on everyone and make a bit of extra cash, because I guarantee you that most people who bought PA and have AA, would buy that add-on in a blink of an eye.
Also just signed up just for this... Had the app (paid version) for years, it's the best I could find and it's been awesome. And would gladly pay again/more for Android Auto integration. Just bought a car with it and it only supports Google Play and Amazon Music, both of which pale in comparison with PA. Please integrate with AA! It is such a pain to use it now (only via Bluetooth, which is mutually exclusive with AA), so I either have to unplug the phone to listen to what's on it (i.e. no navigation), or leave it in AA but can only listen to FM radio...