Smelly

So while at Target one day with the kids, I spot what looks like bird poo on my truck. No knowing any better, I press on it with my finger and low and behold it's rusted from the inside out. Has anyone ever experienced this in this particular spot? I know two years ago my 3rd brake light was leaking and running into the wire channel along the passenger side. Is there any remedy I can seek from Ford for this one? Did this come from the third brake light leaking? The guys at a shop I took it to never saw something like this. It's doing the same exact thing on the drivers side, but it's not this bad yet.

This is on a 2006 F-150 Lariat S-Crew

huffy47

same thing on mine i got it there and right below the fuel door