Stainless steel
Stainless is noticeably denser than regular steels because of the large amounts of nickel and chromium in the alloy. It's not super-hard or bulletproof, it will dent and scratch. What interests me about this pickup's design is the rather sharp corners on body details like the wheel arches, they're an obvious place for stress fractures to start and propagate due to vibration from road travel. Regular curved shapes are stronger and less prone to cracking.
Stainless is also a pig to manufacture compared to conventional vehicle-build grades of steel plate. Elon must be thinking about cross-engineering development from SpaceX's Starship which is being built from stainless steel to sort out the specialist welding, drilling and shaping processes needed to work with stainless. Combining those techniques to work economically and reliably on a car production line is another matter.
My guess was that this announcement was a joke, timed to coincide with the start date of the original Blade Runner movie (21st November 2019). A friend described the pickup as a "pedestrian murder machine" on his blog.
Biting the hand that feeds IT
