wilson,
Not real sure on the two squares but I would assume that they are the "bolt-on" side dams that you attach to the back. The "Gurney Lip" is a small piece of plastic that mounts of the rear wing of the car. It is nothing more than a little strip of lexan that bolts to the rear wing and you can adjust the height for more of less rear DF. Like I said, I dont use the Protoform Speed 8 but from what you have asked these are the 99% best of my knowledge.
IKE