2014 SR5 Rust under bed rail caps.

Any ideas on what to do about this?

 

Well, that's not so great. There were no signs of wear in that area before installing my truck's bed cap (with the plastic rail caps on under it), but it did show up soon afterwards. Can't have my truck bed rusting up. My solution was to tape off the area and coat it with several layers of a spray-in bed liner. I can still see some wear in the area, but none of it has gotten through that spray-in liner so far. If it ever does, I'll put on another coat of spray-in bed liner and add a couple of hard plastic drawer slide strips over that. Those thin strips should fit under the plastic rail caps, but still keep the rail caps off the metal. If you come up with better solutions, let me know.