As I am sure many Mazda owners have discovered, their vehicles do not hold up very well in environments where the roads are salted in winter. My 2002 Protege5 has been an all around great car with this one major failing. First noticed the rust around the rear wheel-wells a few years ago, but it had of course started well before the time I noticed. At this point, the car is most likely a lost cost. Have had to pay for repairs to the sheet metal around the rear wheel wells, the undercarriage below the rear seats, and the fuel pump body - all related to rust. The windshield even started to leak on the driver side column due to the rust that exists between the paint and the glasses rubber seal.

The degree of rust on the rear sub-frame is getting bad enough to make the car a safety concern. Most likely will not pass the next inspection in August 2012, and replacement of the rear sub-frame is likely to cost more than is worth investing into a car with 140,000 miles currently and plenty of rust everywhere else (strut towers, rockers panels). Too bad, as the car runs great and has been a great little car in most every other respect. I believe that other Mazdas experience similar issues with rust, so unless I find myself living in Arizona one day, this will probably be my one and only Mazda.

The car started rusting shortly after its 5yrs body warranty expired. The whole undercarriage and suspension rusted out completely, and it developed a see-through hole in the floor in the rear passenger area. The rear fenders are so rusted that they would no longer hold the rear plastic bumper panel - so I had to use aluminum duct tape to hold it in place. When my mechanic hoisted the car up and had a good look at it - he concluded that Mazda's rust proofing on this model was either non-existent or completely ineffective. When I drive around I see that most of these models have rusted out rear fenders, so this must be an inherent problem - or in other words "DEFECT".