2005 Mariner 3.0 ran rough last Friday, but fine when warmed up. Dealer does pick up and deliver. They called and would do the minimum but advised not to invest anymore in it since road salt has eaten the frame so bad. $200 for a spark plug and coil. This is from the dealer that sold it new to my mom. Going to look at a body on frame Lincoln tomorrow.

 

Disaster would have been the misfire causing the catalytic converter to melt. Disaster would have been a failed COP causing the driver transistor in the ECM shorting out causing a dead miss in that cylinder, leading to converter failure.
Some have replaced the K-frame that is bolted to the bottom of the body. It holds the engine, transmission, and most of the front suspension. If it is that part, you may find one available that can be substituted for your rotten one at a not too high cost. If the body rails are rusted, time to look for something else. In Canada, the rear shock mounts seem to be susceptible to rust, and of course in the Salt States, the same holds true.
Personally, I think salting the roads causes more damage and does not do that much to rid the roads of snow or ice. Better to drive more carefully than to destroy new cars in such a short time.
I would also note that failed cam cover gaskets can allow oil to leak out onto the engine AND oil to leak into the spark plug wells, causing the COP boots to get contaminated and thus allow the spark to jump sideways instead of going to the spark plug. Once oiled, the cannot be cleaned AFAIK. Separate boots are available without COPs if needed.
tom

 

Road salt is deadly to new cars, bridges and the environment. Older times the plows went, till snow was cleared. A little sand on the intersections. I just lost a car to rust, dealer said don't bother trying to fix. Was my work car so salted every day in winter. Retired now so don't have to go out till it's clear and dry.