[njsteve]

Absolutely. It was some time after 1999 that the assembly line switched adhesives on both the Camaros and Firebirds to a far more aggressive adhesive that reacted with the resin transfer molded (RTM) panels. The assembly line also did not prime the underside of the porous, RTM sail panel. As a result, the solvents in the adhesive gradually softened the plastic and ate their way through til the paint would bubble. No amount of sanding and cutting would stop it as it would just come back out an inch away from where it was repaired.

The only real fix was replacing the entire sail panel (or "targa bar" in Porsche speak) with a brand new one (discontinued GM part number 10254708) or one carefully removed from a 1998 and earlier car. The OEM replacement panel has not been available since the late 2000's. Your only choice is a fiberglass replica part they sell on ebay, or an original part removed from an earlier car. The reason that the earlier panels are good is that from 1993 to 1998 the assembly line used a different adhesive which did not affect the panels. That was what I did on this car - got a perfect one from a 1997 in a salvage yard and carefully removed it from the donor car and then had the body shop remove the old one from this car, paint it and install the new one with the modern, plastic-friendly, adhesive that was specified in the technical service bulletin.

Here is the actual TSB dated February 2003, just after they stopped making the cars.