Speaking of defective cheap parts, after a year of ownership my door panel has developed a divet in it where I set my arm on the window sill when I drive. I have had this happen before, but normally it takes like six years.
I'm in the plastics industry, and can tell you that the good plastic is slowly being replaced by the cheapest crap that the cheapest industry will produce in Asia (which is usually polypropylene or ABS). Not trashing Asia, it's just that the cost to produce is many folds cheaper than here. The problems is, many times they are not retooling correctly, which means they may not be adding enough stiffening ribs to the cheap parts. Hence the divet in your part.
It's to the point that You have to go more high end luxury vehicles to retain the good plastic, it's not just Mazda that is doing this. Ah well, guess they have to please the stockholders...