Neoprene seat cover fitting

I installed a set of neoprene seat covers on the front seats of my Prius today. I love the look and feel of them and they seem to fit very nicely except for one area. Where my back rests on the seat the cover isn't flush with the seat. So, when I sit down my back hits the seat cover first and then there is approx. 1" of space between the seat cover and the actual seat.

I believe I have installed the covers properly and all of the seams line up with the edges of the seat. Will the covers ever settle in and become flush/hug the seat or will there always be that gap/space between the cover and the seat in that area? Thanks.