My car was partially apart so I don't know the order of assembly. I assumed the package tray went in first, then the side panels which would help hold it down. Problem is with just the package tray it's way too tight. Putting the insulation under it is out of the question. Is the insulation supposed to be cut back, which would not leave a flat surface all the way across, or is the package tray supposed to be trimmed to fit between the side panels? Any help or pictures would be greatly appreciated. Thanks, Tom