Why won't my podcasts, streamed through Podcast Addict, play through my car radio via USB?

[AC Question]

I have a HTC One M8 and I can't get my podcasts to play through my car radio via USB.

 

[B. Diddy]

Welcome to Android Central! Which car, and is it a factory-installed sound system or an aftermarket? If you're connected via Bluetooth, go to Settings>Bluetooth on the phone, tap the settings icon next to the car system, and make sure Media Audio is checked on. If there is no Media Audio option, then the car system doesn't support streaming audio.