I installed the bar first and laid the panel over the brace to get a rough idea on where to put the tape. For reference one edge of the tape is closer to the edge than I thought it would have to be. When you put the uncut panel over the STB line up the panel with the bolt hole that is located on the rear cargo tray. That should orentate the panel close enough to make your first rough cut. Remember you can always make the hole bigger, cant go the other way :)