I had a compound curve in the corner of my headliner where it rolls down to meet the side and back panel. I used one piece of foam, it was difficult but you can do it if you first place a couple of sheets of wax paper between the foam and the board you are wanting to glue it to. Start in the center of your compound curve and leave that area exposed from the wax paper. Stick it down and smooth it out then move the wax paper out a little on both sides and work the foam down. It may take you more than one attempt to get it right.