The reason why our kits are shorter/smaller that the actual size of the piece we'll cover is because they are meant to be stretched due to the curvature of the lens/body panel.
An analogy would be us trying to cover a globe with a piece of paper. There would be a lot of wrinkles/fingers and it would be impossible for us to full cover it without any wrinkles/creases.
In order to accomplish installation successfully and without wrinkles, the film needs to be stretched. As the film is stretched, the wrinkles disappear.