It starts out as a roughly shaped STEEL piece that is ran through the machine to form the desired shape. The die was designed in Solidworks and water jet cut from 1" steel. We then shape the dies to form the desired contour. It has 3 bend radius's in the piece, we the set up each half to give it just tiny peak in the middle to go with the stock peak in the tail panel. Just a teeny tiny peak.
You can see where we marked the peak in the middle.
Here it is mocked up on the car.
