is there anything behind the screw holding it together, or you just screwed it in. Are those special screws? You used the towel to push the spoiler and trunk together?
Jam rag or something soft in gap between edge of roof and spoiler to push down on spoiler while drilling and putting screws in. Drill hoes small enough so screws bite. Nothing special about screws except use short ones, like 3/8" long.
What a piece of garbage this car is . Mine filled up with mold because of the tons of water that leaks into the car from the panoramic roof plastic frame cracking on both sides of the roof because of the disgusting rear suspension design that twists the car's rear end when going over bumps . Your car body has probably twisted and that's why the hatch now scrapes the roof section