Sadly, not many car OR boat engine manufacturers set up worse case senerio rust/corrosion testing. It IS possible to induce corrosion in a lab but that will not perfectly match what happens with corrosion over time to different metals, much less moisture/rain/water scenerios in so many different environments.
People who live in rust belt and corrosion prone areas have different responsibilities when it comes to their car care. All under-vehicle areas are highly prone--quarter panels are the poster children for corrosion.
If you live in an area that gets any yearly snow, ice, sleet, and your state allows SALT or any NACL mix in sand, spray, or silicates put down to help winter driving then you will be prone to rust/corrosion on your vehicle.
Many states have decent car was facilities to allow washing the underside of the vehicle after each snow event and then the owner manually cleaning around the quarter panels with a high pressure soapy water emulsion.
My father did car restoration in Northeast Illinois as a side line for decades. Every time the salt truck went by he just smiled and smiled.