We did not copy these parts from another supplier. We faithfully reproduced them from factory blueprints (see the BUY IT NOW links for the GM Blueprints). Zip Products research was to simply try and copy other reproductions. We even intentionally produced a few totally phony air dams for them. In line with their phony research, they even copied those too. Avoid their WRINKLED PSA They also screwed up on the GM specified SAE grades of rubber, because they never had any blueprints. At cruises and Corvette shows, I have seen the improper grade items. They are easily detected by the large air cells visible in the rubber. Look at any of your originals and you will hardly see the air cells in the rubber. If you consider these from Zip, only the name is the same. Those dirtbags have been trading on our reputation for accuracy & quality for decades.