I could see where putting an object in the seam where one was not originally intended to go causing stress on the glass and cracking it. Not good, especially if you are attaching a sucker to that glass. Attaching the seasucker to my glass roof already kicks up my worry meter a notch, but its well within the acceptable limit of worry. Putting this anchor thing in the seam and shutting the hatch would elevate this to level higher than I am comfortable with, until I see alot of people reporting on its use on Tesla Model S's, which I don't.