I had our car detailed by the local uphostery shop and I had inquired about the glass separation on some of the cars here. He mentioned that this was a common problem with Mecedes Benz and it would not suprise him if the Crossfire had the same issues.
He did not give any reason as to why, but my guess would be the adheasive given up during hot weather as suggested. I park our car out doors and I have not notice any separation as yet. Sorry for your trouble there, perhaps a good Uphostery shop can make that repair. Good Luck!