I saw the "Killer" at the 2000 OMC picnic (More photos of it are in that album). Had a chance to drive it, but there was this kid who had not driven a GT drooling all over it so I let him take it to the picnic grounds.
Rodney pulled one of the tailights to show me the way he did it. All metal. Just used good old fashioned customizing techniques. Pretty slick. The cut lines on the new fenders were 3 inches wider than stock and he blended them in. Sounds easy but it is a lot of work. I have an article that was published in the old NAOGTC newsletter. I'll try to scan and post it this weekend.