yours being an 07 it still should have the rust warranty on it. Its a 3 yr unlimited mile warranty.

 

My 08 has already had back and front bumper inside rusted out and the lower part of the tailgate started to pit. The dealership has replaced all three since it was under warranty.

 

I'm in Kansas and there is a tad bit of rust in the same spot as the OP is having issus so idk. It's not visible or anything at the moment from the outside but I really do need to take care of the problem before it gets much worse.

 

My '03 has been a plow truck since it was new. This summer the paint started bubbling and rust showing on the edge of the hood and the top of the quarters and fenders. I think next spring I'll fix the hood and get some pocket flares to cover the fender/quarter panel holes. The old girl has too many miles on her to be dumping a lot of cash into it.

 

door seams also rust, my 06 is rusting away, but I keep on track with touch up paint- light sanding...

paint and body work is and allways will be a week link on the 3rd gen Ram.