Our fourth-gen suffered from a common ailment where paint bubbled on the roof hoop. Back in the day, there was a service bulletin on this from GM, but our Z28 is way past its warranty. The problem was caused by some “Earth-friendly” glue used by GM out gassing and jacking up the paint. The right way to fix it is to replace the roof hoop, but the part is no longer available. Later on we’re going to figure out a way to properly tackle the problem, but for now we simply sanded it down in preparation for fresh paint.