Yes, and they do that once, when the glass installed. It’s a static load. While the car is stationary. And there is not a bicycle attached to the suction cup. And windshields are engineered differently than rear windows.Possible but difficult to believe since windshield installers use very similar vacuum suction cups to move these pieces when they are being installed.
Believe me, I would *love* to use a Seasucker on my M3, so I could carry a bike on the roof while I tow my teardrop trailer. But that roof glass is simply not designed to handle that kind of dynamic load for long periods of time, with the car moving at highway speeds. If it were, it would not have cracked. It’s the wrong application for the Seasucker.
Still trying to determine if the Seasucker will stick to the roof of the trailer. It’s an exotic aluminum composite material called Azdel.