nextzett Gummi Pflege Rubber Care Stick Car Weatherstrip & Seal Conditioner Prevents Freezing, Cracking, Fading 3.4 fl oz

In my 991 I also dealt with the creaky sunroof that the dealer couldn't figure out. I has success going around the seams with a rubber trim conditioner. It fixed it immediately! I do have to reapply every year or so. It's this gummi pflege stick - https://a.co/d/027uAq5u

Congrats! Took seven years for mine to start showing cracks in the dome, at which time I applied this gummi pflege; it repaired the cracks and no more have formed since - that was four years ago. https://www.amazon.com/dp/B004B8GTQG?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1