Just saw more responses on the 2nd page.
I can provide more details when I get the car back. I think it's too pre-mature to go through the lawsuit/lemon route, but will keep that in mind if the problem persists/comes back.
I am going to contact Mazda corporate to ask for an extended warranty (both bumper-to-bumper and powertrain with $0 deductibles).
Do people know what's the duration of Mazda's extended warranty (Total Confidence and Powertrain Confidence)? The website doesn't show any plan details, so maybe there is flexibility in it. Is a 5 year/60k miles bumper-to-bumper and 10 year/120k miles powertrain a reasonable request?
I think mine is similar to cln. Its noticeable to me, but I have to point it out for people to hear. How loud was yours?