Unfortunately, Mazda 3 owners are condemned to a life of rapid tire wear, and there is not much that can be done to change this. The Mazda 3 is engineered with negative camber on the rear wheels. This is a permanent design feature and cannot be altered. Although the negative camber helps provide good handling, it also causes tires to wear rapidly on the inside edges. Owners most often notice this when they rotate their tires for the first time. When the tires that had been on the rear are rotated to the front, the excessive wear on the inside edges of the tires causes very loud road noise. If you have directional tires that can only be rotated between front and rear (as opposed to side-to-side), the problem is likely to be worse. The noise will be its worst at lower speeds.

The Mazda 3 is a great car in most ways, but the tire wear problem is a definite negative point... and there isn't a thing you can do to change it. You can (and should) make sure the car is aligned properly, and this may minimize the problem. But the problem will not go away. I like my 3, but if I had known this, I most definitely would not have bought the car.