I just recently bought a car plate protector for my car and opened found some kind of sticker with silicon like button with the screws for the car plate protector I just wondering if those are for?

I've uploaded a pic right here: http://i1225.photobucket.com/albums/...5/DSC02301.jpg

as you can see there is a silicon, button like stuff next to the screws, I am guessing those are to be used as seperators for the plate cover and the surface of the car? But there are only for of those where should I stick them?