Help Civic Interior to Integra Interior!!!!!

Hi all I know this is kinda of gay but here goes. My friend parted out his leather integra seats front and back. He then gave them to me because I want to fit them into my 99 Civic Hatchback. The front seats fit in perfect other then a little mod but it worked. Now can yah help me with the back, the rear back rest fit into place but the bottom part of the seat doesn't there is like a 3 inch gap on both sizes. I wanna make this work would I have to do some custom work like make somethang or add somethang to fill in the gaps so it doesn't look GAY. Please help I wanna make this work and I'm not giving up any ideas on wat I should do????