Here ya go, 5 years and ~72K miles in salty New England. Not a spec of rust, NONE. (please pardon the dirt, truck needs a bath) I have not painted it, that is the factory paint.
My method: multiple coats of Amsoil HD Metal Protector. Love the stuff, I always have 2-3 cans available. It was just starting to show some rust at the welds when I bought it 2 years ago, so I gave it 3-4 coats over several weeks. Let it cure between coats. Now I give it a couple of maintenance coats every year, usually when I'm changing the oil and doing the tire rotation.
I had an '04 Highlander at one point, bought it used in '07. They are very popular around here and I could see that it was a rust problem, so I started the same treatment. I saw that car today, it has over 250K miles on it, and the hitch still looks almost new. Wish I could say the same for the rest of the underbody. Still, great car that has a lot more miles in it.
