Potential Corksport product? Seems like a chronic shortcoming in the design.This is really great information. Thank you for posting it. I have been trying to figure this out for quite some time. I don't know how clear my audio file was but did the sound in my upload sound like your sound?
I'm all in on Mazda though, I find myself liking the car more and more in spite of it's flaws (and there are a few minor irks piling up) which I think says a lot.
I have had that exact creak every so often. I'll try to keep note of the weather. We have a street with large speed bumps every few hundred feet, so i'm hitting them daily.
I usually have a single popping sound when turning left or right from a stop (if you took your audio file and just clipped the initial pop without the creak).