What is the holdup??
Why is this not a thing yet? Why wasn't Android Auto support added to the roadmap as soon as it was announced (*cough* like your competitors *cough*)? If this was supported, SoundCloud's usage and userbase would balloon.
My Spotify usage has increased at least 3x and my SoundCloud usage has decreased at least 3x SOLELY because of Android Auto support or the lack thereof. I love the service, but I'm THIS close to cancelling my paid subscription ONLY BECAUSE I cannot use the service where I listen to music the most, like I can with (all of) your competitors' apps. I'm not the only one who feels this way. Get the picture?
SoundCloud now is pretty much the ONLY major (PAID) streaming music service which does NOT support Android Auto. The ONLY one. Even TIDAL supports it. TIDAL, which has all of 75 users! Android Auto has been available for years and is reaching maturity, so what's the excuse? Why does SoundCloud refuse to implement support for this? What the hell?
Give your users SOMETHING. Your users have been asking about this for years, and SoundCloud's silence on the matter makes it even MORE frustrating. If your goal is to lose subscribers, good job, this is how you lose subscribers.
This can't take more than a few sprints to implement. Even if it takes double, triple, ten times that, it's worth the development time. Crazy idea, but maybe SoundCloud should start paying attention to what their users request if they want to retain subscribers and improve their performance.