I've posted this on Apple's support forum as well, but thought there was more likelihood of someone here having a similar setup and issue/solution.
I have a Pioneer AVIC-X930BT http://www.pioneerelectronics.com/PUSA/Car/GPS-Navigation/AVIC-X930BT
with the 30-pin iPod/iPhone adaptor CD-IU51V http://www.pioneerelectronics.com/PUSA/Portable/iPod-And-Bluetooth-Accessories/CD-IU51V
in my car.
I upgraded my iPhone4 to iPhone5 back in October and started using Waze about the same time. Since my commute is generally an hour+ each way, and I was ending up with a totally dead battery by the end of the day, I bought the Apple Lightning 30-pin adaptor after a couple months. I started noticing my GPS signal being dropped from anywhere from a few seconds to the entire drive so reinstalled iOS and it still did the same so took it into Apple and they decided after looking at the error logs it had a bad GPS antenna and replaced the phone. New phone does the same and I then realized it only does this when plugged in. I've tried to re-create this with the Lightning/30Pin when plugged in inside but can't. Only when in the car.
So if I reliably want to use Waze, I can't have it charging.
Have others powering an iPhone5 thru a Pioneer noticed this?