When the Aspen/Volare cars were being designed, Chrysler was already in financial crisis mode, so saving money in "unseen" area of the vehicle could be important. Whereas prior cars had had a "liner" or inner fender between the tires and the front fender underside, IIFC the A/V cars had none. So it was only the basic primer coating on that part of the fenders . . . just like a 1950s GM pickup truck. As that primer got eroded wtih road debris from the tires, certainly bare metal was exposed and "rust" happened. Add winter road saltand things just got worse.
The A/V cars also had more recalls than many other cars, too. Like the 1-bbl carb base gaskets that would fail and cause driveability issues. Poor and inexpensive sourcing most probably led to Chrysler having problems where none had existed previoiusly. With all due respect, assembly line QC and dealer Pre-Delivery Inspection/Service could have been "side issue" problems, too.
To Ross's comment about the AutoPilot issues, considering how low of an installation rate on that option, that it would have been more on Imperials and New Yorkers than Newports or Furys (although it was available on them), and something which most dealer techs had never seen (other than in the larger metro areas) in "Smaller Town USA" back then. It would have been very easy to keep "unintended acceleration" issues very quiet, I suspect.
Notification of that issue was probably in a "Dealer Letter" rather than in a TSB per se? Dealer principals saw it, the service manager saw it, and if they weren't ordering their cars with that option, the letter was "filed". This was also in eras when ONLY dealers got or could get TSBs, too. If a TSB might have been issued, it was filed in the appropriate folder (along with other TSBs that did not apply "to the vehicles we order and sell").
Just some observations,
CBODY67