Bi-directional audio in CarPlay

General question: Working on an app that streams high-quality audio as well as listens for voice prompts from the user. This is an integral part of the app. The audio quality when using headphones (wired and BlueTooth) is great, but when using in CarPlay (wired or wireless), the audio output has no depth, is very flat and lower quality.

I know some apps (like Spotify) that only stream out audio maintain their audio quality (though they do have some EQ adjustability built into their app) and wondering if the bi-directional nature of the audio in our app is the culprit.

Any suggestions would be most helpful.