Car Stereo Issue: Sound plays through iPod on car start

Hello everyone,

I've been experiencing a strange issue with my iPhone 5 / iPod Touch 5th gen for awhile now on various car stereos. In two different vehicles with different stereos, I can connect my iPod through a lightning to 30 pin adapter and music plays just fine through the car stereo.

However, almost every time I turn off the car and go away for at least 30 minutes, when I return and start the car, there is no audio playing through the car speakers. Instead, the iPod connects and charges through the stereo but plays audio back through it's own speaker. So I have to reach into the glovebox, disconnect the iPod, and reconnect it. This fixes it but is extremly annoying because I have to do this every single time.

I want to leave my iPod in my glove box and be able to have music play correctly when I start the car (through the actual stereo).

I've tried researching this but found nothing. I've tried completely erasing and restoring my music collection and this didn't fix it.

Ideas? Please help.