Don't have to be that way,
You can fight back...
Just use the right rustproofing oil, per my earlier posting, normal engine oil oxidants feed the rust. What you want to do is cut off the oxygon from the rust and it no longer "oxidizes" the iron.... We battle rust big time here in Oz, with something like 15,000 miles of coastline to drive... Ha!
Open door panels from the inside and give it a spray once a year with the proper rustproofing material.. Same on the Tailgate. Same underneath if it is showing any signs. Even the chassis rails... My 1993 had NO RUST at all at the time I sold it a few four or so years ago. On the beach, salt, and all.
Regards from Oz... lone Ranger