I understand what you guys are saying, and there is truth there... but .. regardless of what the manufacturer does, it is incumbent on the owner/operator to maintain and preserve the vehicle. I've always kept my vehicles 'clean' from new, even to washing out the wheel wells, and underneath, especially after having driven in nasty conditions (and I'm in the south, so opportunities to drive on salted roads have been very minimal, but I've driven in sandy situations, even on Daytona beach, but I have never failed after driving in situations where the undercarriage (and all it's nooks and cranny's) have opportunities to trap road salts, etc, .. I've always made attempt to *clean* underneath and 'flush out' all the salts and contaminants as soon after as possible. I've used coin car washes and their high pressure washers much more often for washing underneath and wheel wells than I have for cleaning the top side of a car...
How many of those 'rusted down' cars you've worked on, do you think got treated to that kind of care? Did the manufacturers PROOF their vehicles so that they'd last 40 or 50 years *regardless* of how they got treated? No.. and should they have? No again.... If the owner wants to preserve the things they own, they will.. otherwise.. they won't get preserved regardless of what the manufacturer did.