I had a very similar issue on my 2005. I was told that the seam where the metals meet are highly suspect to this issue. As a matter of fact I would bet that nearly everyone from 2004 on up have this issue in various conditions. I regularly check the seams all around my hood as this appears to be the only area with the problem. Only repair is to sand,primer and reprint.
2011Premium Grabber Blue GT Convertible -GTYUP
1 of 56 as optioned !!!