Broken rear shock absorber brackets seem to be a chronic problem on the Mazda 3 for several years in a row. My right one has about 85,000 miles and my left just 100,000. They're relatively easy to fix if you have a set of socket wrenches and some patience. Many YouTube videos can show you how. Dormans are an exact replacement, cheaper than others and get the job done perfectly. If I leave this car for another 100,000 miles I suspect they will crack too. They don't rust. These are fatigue failures from the constant up and down movement and the aluminum just fails. If you want something that will last longer, look for a more durable and more expensive replacement. I dared them. So far, so good.