To my knowledge, the Toyota rust warranty covers the body only and it has to rust all the way through. A friend of mine w/ a landcruiser lives right on the ocean in San Diego, parked the vehicle outside for 3 yrs. There were rust spots on the tailgate, dealer wouldn't cover it under warranty since it didn't rust through. Tar (the oil stuff they spray on asphalt roads before re-sealing) works great protecting any metal. Lasts a lot longer than waxes. Only thing you can do now is to use a wire wheel/sanding disc to remove the rust, reprime, and repaint. Then put the rust coating over the paint. If there are any holes in the frame (not from rust, but factory holes), you want to spray the tar or coating inside there, too, to reduce rusting from the inside out. You also want to coat the inside of the tailgate & doors. I had my pickup coated at Ziebarts when i moved to upstate NY and after 6 yrs, the only thing that rusted was the tailgate. Body had no rust at all.