Manfrotto 241V Suction Grip with Camera Support (Black)

i got this to do an in-car timelapse video with my dslr. i drive a buick century which is has fairly large front and back windshields. this is a professional piece of equipment - it is built well and all that good stuff. the problem is that it is limited in where and how you can use it. the suction part is flat and very rigid, which means you can only use it on pretty much a completely flat surface. the way it becomes suctioned to the surface is by pressing the cup against that surface, and then you push a button which i assume sucks out any air and creates a vacuum. you have to press the button a lot to get it to be a solid connection, and as time goes by you need to occasionally press the button more because it will lose grip very slowly.

The suction cup works great on flat glass, but looses suction on auto glass due to the curve. It did securely hold a Canon 7D with a 24-105 lens, but I had to keep pumping it every few minutes.