The f-panels have flanges on the rear edge that will attach to the panels that close off the rear of the front wheel wells. Most people rivet these panels on, but apparently they interfere with getting the body on and off, so some people recommend making them removable. I drilled a series of holes and added rivnuts to them so that I will be able to attach the panels with screws.
I also added a couple of rivnuts to the inside of the left f-panel to attach the control box for the electric power steering. You can also see a rivnut in the chassis that will be the grounding point for the electric power steering system.