When attached to the window the cradle is incredibly stable and the suction is strong enough that you can bend the arm while connected to the glass. I took this as an excuse to drive like a jerk by hitting every pothole I could find and taking corners much faster than I needed to, all while putting my own personal PSP on the line. I even attached it to a sliding glass door with a PSP in it and shut it roughly against the doorstop and the PSP moved very little. I doubt any real life situations would occur that would create the same conditions that I did that afternoon.