The studs I was referring to on mine are little mushroom head things attached to the body and you just slide the keyholed plastic clips on them. Only holes are for the screws I mentioned. And those were definite leak points on mine Headliner was water damaged from them.
We always called those “clip tits”. For screws on the ends I always put dab of clear silicone in the hole before running the screw in. Never had a leaker.
