That improvement came as a result of market driven forces and not Government Certification requirements.
because the stamping tooling wears out eventually there is a need to make new tooling.
if you are going to make new tooling why not make a new exciting sales stimulating car?
which allows the automotive engineers to update their designs.
my father discussed one day my incredible little car. 270,000 km and still delivering new car fuel consumptions.
"when all my cars got to 50,000 miles they were stuffed and required a total rebuild if you wanted to keep them."
I saw photos of a daewoo nubira that needed the head off at 280,000km. the honing marks hadn't even begun to wear off the cylinder walls.
the benefits of an steadily improving technology.