GMs (Central Office Production Order) COPO program was a great example of this. It was for example originally for somebody owning a taxi fleet wanting maybe 2 dozen or more 4 door Biscaynes in taxi yellow with straight 6 engines and 3 on the tree transmissions. By virtue of it allowing you to order whatever the heck you wanted, It also allowed somebody to order a base model 1969 Camaro or Chevelle with an all aluminum 427 a 4 speed and 12 bolt rear along with heavy duty brakes. A combo that was not offered on the dealer option sheet in 1969. A savvy dealer sales guy or customer in the know back then could do just that. And people did just that. COPO performance cars are pretty rare as the ordering system to manufacture one wasnt widely known. However Chevrolet Dealers like Yenko, Baldwin, and Nickey did use the COPO ordering sheets then built their own supercars in 1969 with the big V8s and heavy duty drivelines already installed when they rolled off the car carriers. Add special stripes, hood pins, hood tach, some cragar SS mag wheels, special dealer performance badging, and viola, instant supercar. Think Mr Norms GSS darts too. Similar idea.