the dark areas are because of the fisheye effect on the camera,thats why you,ll also notice the sidepods of the car look more curved in than normal..i think the actual fisheye effect is impossible to make, but any sort of overlay filter is possible,ive made a few myself in the past,its pretty simple,you just make a semi transparent tga file with the desired effect,then use GPxCinfo in gpx patch to show it in game..