Driving in road salt, beach sand, or standing water at the beach is not covered under warranty. That is on the driver for failing to avoid it. If you live in the salt belt, that is a choice, sometimes good, sometimes bad. IMOSorry for all the grief you are getting. Something is amiss here. Nothing should look like that in such a short time.
Not sure if your state consumer agency could get into this. They are usually pretty good with these things.
I would go in the direction of significant loss in resale value and look for compensation if replacement is off the table.
That may be a rough road but a consumer agency could help.
Best of luck