We had alot of the 404's and 504's at the wrecking yard I worked at in the mid-80's. YES to the rust issue!!
But of all the people coming in wanting parts for them, I always asked how they liked the car, and all of them loved the things, mostly for the comfortable ride.
Some of the engineering was kinda wierd as I remember, and some of the stuff wasn't easy to work on. Like the "torque-tube" drive shaft set-up.
Then there was the 3 lug-bolts per wheel
