I noticed RUST on Rear Panel behind the rear bumper support bar on the body panel

[RED2001GT]

I was looking at my 02 Mustang at the body shop today and I noticed that there's a horizontal small line of rust about 1' foot long in horizontal length just behind the rear bumper bar on the body panel.
I believe that the area which I am talking about is just right below the exterior seam which is on the rear body panel just directly behind the rear bumper bar. Is this a very common area for the 2002 Mustang to develop rust?
I have driven my Mustang thru 5 New England Northeast winters so far. I am worried that the rust will eat thru and that eventually water will get into the trunk from the rear panel. So far, the rust is just minimal, but it's in an area where it is impossible to see because the rear bumper cover "hides" this particular area. Is there a design flaw in our 2002 Mustangs which will cause rust to appear on the rear body panel which I am describing?
The bumper cover covers this panel and it cannot be seen unless the rear bumper is taken off the car.

 

[RED2001GT]

Anybody?

 

[Kilgore Trout]

Clean up the rust and slap some rustoleum on it

 

[n0v8or]

Is there any evidence of paint at that location? On my '03, there is no paint on metal not readily visible from the outside. All metal behind the bumper covers, on the underside, behind interior trim pieces, and under the instrument panel, were already rusted as delivered new (22 miles) from the factory. I painted as much as I could myself. It seems to be just Ford's way of saving a few pennies.

 

[XtorT'r]

My car developed some rust on a few spots over the last coupel years. I payed to have it fixed, I wont drive a rust bucket. But thats what I get for driving a stang in the winter.

 

[RED2001GT]

Is there any evidence of paint at that location? On my '03, there is no paint on metal not readily visible from the outside. All metal behind the bumper covers, on the underside, behind interior trim pieces, and under the instrument panel, were already rusted as delivered new (22 miles) from the factory. I painted as much as I could myself. It seems to be just Ford's way of saving a few pennies.

Oh yes. There is paint on that location which I am describing which has surface rust on it. It's the same color paint as the rest of the car which is Torch Red. The surface rust is there because all the salt water from the melted snow/ice gets lodged in this area and there is no way to pressure spray the area to wash away the salty water that goes in there. It's directly behind the rear bumper cover on the body panel below the rear license plate. This particular area is "hidden" and cannot be seen unless you take the rear plastic bumper cover off.

 

[RED2001GT]

My car developed some rust on a few spots over the last coupel years. I payed to have it fixed, I wont drive a rust bucket. But thats what I get for driving a stang in the winter.

In what areas of you Mustang did the rust develop? How did you fix it? I would like to know because my Mustang will become 5 years old in the beginning of January 2007. My car is a 2002 Mustang and it currently has some surface rust on the radiator support and on a few seams on the panels underneath the car on the undercarraige. And it also has some surface rust on the rear panel just behind the rear bumper cover.