Update: parts are in, and the car goes in at 8 am Monday morning.
Warranty status: COVERED!
However, the stereo situation, like the power window one, was not all that it seemed. Apparently, the volume WILL change according to the vehicle's speed. WTF? I have two frickin' sets of volume controls...in-dash and on the steering wheel. Why the HELL do I need my car stereo tied to the accelerator and brakes?!
WTF was Mazda (or Ford) thinking?
Besides, this never even occurred until a few weeks ago. So the dealer is going to make some sort of adjustment to allow me to change the volume myself ONLY!
I was also having issues with another window, so that's being fixed too at no charge (motor issue, it seems).