I just posted this in cuda challenger gallor, but meant to post it here.
Stereolithography would produce an exact "resin" duplicate of an original grill. The OEM grill would need to be modeled using CAD, such as Solidworks or Catia. Both of these software can model to 7 decimal places, though we used only 4 places; IE 0.0001 accuracy on the model, and +/- 0.005 on the actual parts if required).
The lithography resin model could then be used to make a mold, or use the part as-is though they are costly. I have some experience with this process; the stereolithography models are perfect in every detail with accuracy to within 0.010 if I remember correctly.
Here's a quote from Hot Rod Magazine article on an LS7 "resin" intake manifold:
"Despite its delicate appearance, the clear-resin stereo lithography intake manifold proved very tough on the dyno, shrugging off a couple of wicked backfires from a computer-related timing glitch. We've been told that similar manifolds have even passed 24-hour in-car durability tests".
Here's pics of the LS7 intake manifold and a few other parts. Pics of the other parts are from
http://www.metrorp.com/automotive.php
