Plastics not a bad thing. I mean, it doesn't rust. And mostly will out last the whole car.
last i checked, aluminum will always outlast plastic without rusting, aluminum will also never get brittle and just crumble in under 100k miles.
there is only one upside to using plastic parts, and that is cost (for the manufacture) plastic fades over time, plastic get brittle over time. and every day i see first hand at work how plastic will definitely not out last the car.
tons of cars that come into my shop that are over 10 years old have tons of little stupid sh!t broken, door handles, window cranks, seat levers, hood poppers, trunk levers, dash trim pieces, window switches...
ever take the dash apart in a 10 year old miata? all of the dash panels will basically crumble in your hands.
lets look at just the LS for example,
degas bottle (doesn't out last the car),
all of the plastic cooling parts (doesn't out last the car),
all the little plastic push pins under the hood (doesn't out last the car)
the locking clips on the coil harnesses (doesn't out last the car)
of course the heat weaken the plastic right, parts made of plastic not subjected to under hood temps much fair much better right?
when the window regulator breaks, what part is it that always breaks??? thats right, the plastic parts (doesn't out last the car)
how about any, no wait, how about every button on the dash or center console (message center buttons, traction control, parking brake...) (doesn't out last the car)
the latch that doesn't hold my center console lid down anymore (doesn't out last the car)
does anything say classy like wood grain looking plastic panels??
so I'm sorry, could you please explain to me why you think plastic parts are so great other than by using them, it brings the price of the car down? because to me, it seems like a lot of our problems are due to these plastic parts you so love.