mazda knows about the rust issues and and many of the other problems that plagued Mazda owners, such as the defective door lock. The only did something because they were pressured by the insurance companies, police, and press. The pending class action lawsuit likely also had something to do with it.
Like always, repairing a problem always comes to statistics and dollars. Mazda looks at the cost of fixing the issue at the source (i.e. changing the manufacturing process of the car) vs paying out to have it fixed later and they decided it would cost less to pay out later. I'm sure they have formula's that take into account all sorts of stuff (including customer satisfaction or rather, dissatisfaction and "goodwill" costs, etc) but they must have still thought that the cost of fixing the problem later would be less than addressing it at the source.
The same rust problem will likely present itself with the 2007s+. The rust issue is just starting to show up in the 2005s and 2006s in 2008 and 2009.
Even the APA is aware of the rust problem. And when a prospective buyer of your Mazda looks at it and sees that it's been painted, all sorts of bells and whistles will go off. Your resale value will take a huge hit.
If any one says mazda
always does the right thing must have some affiliation with mazda
