Fit and Finish are two terms used often, because they relate to quality and craftsmanship of auto manufacturing.
It's easy to make one model perfect; quite another to duplicate at the rate of 60 units per hour.
If you recall, it wasn't that long ago that American automakers were criticized heavily for not meeting the same quality standards as foreign automakers. That has since changed.
Fits relate to how all the parts relate to one another in a final assembly.
Take the door gaps, for example. The goal for every automaker is to make the gap as small as possible and with as little variation as possible.
A quality inspector will likely use a ball gage. This measures the variation in assembly; and, by the way, applies to fenders and interior panels.
The finish has to do with the quality of the Class-"A" or show surface. It may be painted or, in the case of an interior panel, may be textured.
The critical aspect of exterior paint finish is that it be contiguous; meaning constantly changing profile smoothly without any creases; plus it has to be smooth without that orange peel look.
Class-A surface designers literally use the CAD computer and check that the digital design is perfect first. The next stage is attaining that perfection in manufacturing. That's why making autos is not a simple business.
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About the Author: After 39 years in the auto industry as a design engineer, Frank Sherosky now trades stocks and writes articles, books and ebooks via authorfrank.com, but may be contacted here by email: [email protected]