I have ben fortunate not to have the problem with my 323. When I bought it in 2004, my dealer recommended that I be careful not to stand on the skylights when on deck. Possibly that has helped to prolong the life of the seals. It does not look like a fun job to have to remove and rebed those panels. Possibly a good grade of glass adhesive such as that used by automotive windshield installers would have sufficient flexibility to retain a seal. It would be exteremely important to be certain that the mating surfaces were spotlessly clean before rebedding.