Okay, so, I installed nothing that wasn't required for Android Auto. This morning, it connected just fine and I did probably 3+ hours of navigation through Android Auto without problem.
Then, I installed the BeyondPod beta and, sure enough, crashed about 15 minutes later. I then uninstalled BeyondPod, went back to navigation again, and it crashed again after about 15 minutes!
So, I'm resetting again, and am going to try installing Spotify but no BeyondPod. We'll see what happens after that.