Just a general comment re: manufacturing vs. assembly.
Most if not all of a vehicles components/parts are manufactured separately (off site) from an assembly plant.
They call them assembly plants for a reason. That is just the place where all of the manufactured pieces are put together to make a finished car.
I suspect (it's just a guess though), that most, if not all, of the parts used to assemble a Mazda in Mexico come from the same manufacturer as those parts used in a Japanese assembly plant.
They are not going to source identical parts and components from two different companies or manufacturers just because the assembly plant is in a different country.
That wouldn't make economic sense.
I'm pretty sure you can buy a Mazda assembled in either country with complete confidence.
