Rear hatch pistons failed.
Sliding side door came off its rails.
Power steering pump failed while the car was in motion.
Unexpected lag or jumpiness when accelerating.
Eats front brake pads twice as quickly as other cars in its division.
This was not love at first sight, for us, it was more a matter of finding the right car to fit our family needs. That being 2 young children, dog, large stroller and road trips around the area.
The first week found us with a cracked rear hatch strut. The gas cylinder gave out after 4 days or 200km's. Since I needed something out of the back, I opened up the sliding door and it immediately fell off the hinges.
The next issue was my own fault. I was in line at a drive through coffee shop playing with my change, a quarter slipped through the gap in the steering wheel, and must've landed on some wires, and the horn went off. In the drive through. It stayed on for the next 1/2 hour until I could fish out the change with a coat hook. I'm pretty sure that there is still money floating around in there, and that one day, it's going to set off the horn again.
After 40,000km's, we were told that we would need brakes all the way around the car. The cost was $800 and not covered by warranty. My Honda Civic didn't need brakes until 80,000km's.
One time on a major highway when I was driving just over the speed limit of 60mph / 100km/h, the power steering failed. I could not turn the car left or right without a LOT of effort. If it was my wife driving, she wouldn't have the strength to move the car at all. If I was on a off or on ramp, there is a strong chance that myself and / or my wife and kids would've been injured in a crash. It wasn't until 2 years later that a recall was placed on these power steering pumps.
Our power steering pump required a week of service, and had to have the front of the car removed to get at it. For that week, we had no baby seats, which made transportation to and from our children's daycare difficult.
The mileage is slowly getting better. At first, it was about 11 liters / 100km. Now it is down to 7 liters / 100km.
I would not recommend any Mazda.. ever.