sorry, but i dont fully understand the question? i think your installing new aftermarket sides. if so diff. manufactures do diff. things, for instance on my 95 ac, i installed my VIS z3 skirts over the stock ones and just drilled a couple of holes in the front and along the top to conect them to the factory skirts, the z3 skirts had a gap between the door seal and the new skirts, by using the factory skirts it filled this in, hope this helps