Most late model F-Bodys have a problem or will start to have a problem with the "sail panel" on their roofs. Mine has started to bubble up, especially when it's in the sun/heat.
In 1999, GM changed the glue that holds that piece on the car and now it is releasing a gas causing bubbles in the paint.
So far I'm not having any luck getting this fixed.
For all the info and the TSB, go here:
http://www.ls1tech.com/forums/showthread.php?t=308546