indeed to try as there is no sun (!) I have placed on my bay window and left and from the reception. They have not moved! Yesterday I put them on the front window of the Twingo because the cat is placed next to my daughter when she led in her cage and to make sure it does not have an ounce of sun, I placed the two side by side in overlapping them and it's really nickel !! they do not move and are more discreet because blacks are super easy pose and personally I did not have to worry suckers twisted not to be able to have the visor because I took much of the time placed before use.