Does anyone have a recommendation for a good android auto app that plays music stored on the phone?
I like to download podcasts/reviews and listen to them. (I have a limited data plan).

I've been trying poweramp but it's very glitchy.
It likes to go into this mode where it only plays about 5 seconds of a song and then switches to the next one.

 

That's a strange glitch - playing songs 5 seconds at a time.
I went through ALL the settings thinking Poweramp had a "scan" option (like radios) but couldn't find anything.
Try re-installing the app OR change all your settings to default.
Also, try contacting customer service.

I've been using Poweramp Full Version for a few years without that glitch.
The glitch I've come across is the Playlist changing to ALL when switching from car to car or playing from my cell phone directly.