Currently working with Mazda to see if they will cover it under warranty. I'm under the miles limit (50k) but over the year (5 years).

Update from Sep 4, 2018: To update this complaint, it did end up being a transmission problem. :( I don't know the exact details but the shop said that basically a bearing went out and damaged parts of the transmission. Final repair bill - just under $5k!

The biggest lesson I took away from this: don't rely on 1 data point - I had a 2008 3 prior to this that had zero issues so I thought that meant I'd be ok declining the extended warranty when I bought this one used. I figured I had slim odds of encountering a bill in excess of the $2k they wanted. I bet poorly. :(

I will give Mazda some credit. We started noticing the issue right after the 60k / 5 year warranty ran out (still under mileage but over the years by about 5 months). They did offer to pay part of the bill as a reward for being a loyal customer to both the brand and the dealer I took it too. I ended up taking it to an independent shop I trusted but the offer was appreciated.

Hope you have better luck than I did!

2012 Mazda S six speed manual under original manufacture warranty.

Purchased as Certified pre-owned Mazda with 12k miles in April 2014.

While shifting from 3 to 4th gear, the gear would grind. The transmission would not jump out of gear.

I reported the problem to the Mazda service department. Head technician rode with me and he verified complaint. He told me he did not need to hear anymore and to make an appointment with the service writer and to tell him it was a verifiable concern. Appointment was made the following week.

During the week prior to appointment the grinding stopped. Service department had the vehicle for 24 hours and called me to state they could not verify the concern as the problem was not repeatable. Advised for me to take the car back to them when the problem re-occurred. Even though the head technician had driven with me and heard and saw the shifting problem and it was still under Warranty, they could not do anything unless it was repeatable.