Given the smooth and seamless nature of the metal skin on the Z isn't it wise to leave the gravel protection on the areas that come on the stock car? I occasionally hear a rock or two kick up under the car but I never see a dent or scratch on the car from it. I attribute this to the gravel skin we have on the bottom of the car. No matter what, good luck with the car. I'm sure it will look better than ever when it's finished!