Recently, someone was wondering what to do about their roof squeaking and creaking. GM has a 50Ml bottle of silicone emulsion that you can brush on the roof panel rubbers. I do mine about twice a summer and seems to keep the annoying noises away. AC Delco part number 1 # 10953014
With how bad our roads have become these last couple of years I might just leave the top out. Surprising how little rain enters the car at relatively low speeds... until we have to stop.