Originally Posted by LongSword

The trunk is the ISF spoiler, idk what the roof one is called. If yours was wiggling then yeah it flew off. you should've tried to remove it at that point. Like i said before when i tilted my spoiler while aligning it and it slightly hit the trunk, that thing was stuck on there. Like an inch of tape touched the trunk but I couldn't remove the damn thing (Maybe I need to hit the weight room). And once I placed the rest of it on the trunk and pushed down, forget it. Thing might as well be molded on. It's been raining every afternoon over here in Miami so I hope the tape and adhesion bonded well with all the humidity but so far all signs point to yes.

Or maybe it was the way you placed the tape on the spoiler side. Maybe it wasn't gripping to it's full potential and just slightly touching both surfaces.