Other than the black rims and more darkened chrome + trim that comes with the Carbon Edition, I haven't done anything else other than rubber mats including the rear cargo area and the retracting cargo cover. I have the red seats so I have some red stuff inside to match. My tax return covered all of that thankfully, plus I bought it all off of BAM Auto Parts so their price was lower for the exact same OEM stuff. The previous owner had Mazda install illuminated door sills, window & sunroof visors, roof rails, and crossbars for the roof rails. I love the look and the fact that it's all OEM!

 

Not sure maintenance has anything to do with it. Seems to come out of nowhere. Some reported it happened just after getting service. Of course having regular service is smart and maybe they would catch it early.