The general term used to describe this body development approach is functional build. Typically, prototypes are constructed from the regular production dies obtained during the die construction phase of development. Manufacturers evaluate these components in relation to other body parts. Thus, components do not necessarily have to strictly comply with their original print specifications. Functional build manufacturers treat the original specifications as 'targets' rather than absolute requirements.
Manufacturers refine car bodies around the stampings.
The important consideration here is whether a component can assemble properly with others to produce a final car body of sufficient quality. Suppose the mean dimension on both flanges is not within specification. In some cases, the manufacturer may be able to close this weld gap by moving a tooling locator. Here, no die rework is necessary. Moving a tooling locator to correct a problem is often cheaper than the less exact die rework process.