Re: The 2016 Ford Taurus.
Not concepts.... design ideas.
Design starts with flight of fancy drawings that have nothing to do with practicality or a view to producing exactly that design. As designs go through the development, some aspects different designs are chosen. A tail light idea on one might be combined with side sheetmetal sculpture of another. A grill on another idea might be combined with the headlights and the hood sculpture of another. then various drawings and designs of these themes are done, with themes chosen.
Once the general design theme is chosen, then.... and this is the important part.... the designs start being converted to make them practical!.
This means that these designs have to be fitted over an architecture based on certain hardpoints (basically, converting a design to conform to the profile of the platform it's going to be built on). Design ideas don't have to be done with regard to how an engine and cooling systems will fit under the hood. Nor does design ideas have to worry about how you and your passengers will fit inside, or how much luggage space you'll have. Design ideas don't have to worry about crumple zones or a myrad of other things that platform engineers have to be concerned with.
Then even after designs have been adapted to structures, then comes additional design tuning. Something that might look great in design might suck eggs when it comes to being aerodynamic. Some parts of a design idea may cause excessive wind noise. Another part of a design idea might be expensive or impossible to produce as is by stamping sheetmetal, and have to be revised. The 2nd gen Camaro has an issue with this when in early stampings, it's rear quarter panel stampings often produced wrinkled sheetmetal. Another example (also Camaro) involved 3rd gens all glass compound formed, rear hatch which would occasionally shatter in early prototypes. Sometimes certain parts have to be toned down.
Notice that I didn't even include feedback from styling clinics (which GM though GM has reduced it's reliance on them, still gathers select people for feedback). Cooling is also a huge item that alters design later in the game. Then there's numerous final design tweaks (rounding design edges that might cause injury in accidents, new ideas with headlight or tail light details, new plans to sell the vehicle in a different market which can alter additional small areas of design.
In the end, what you end up with are vehicles where you can see various parts of a original design ideas, but typically the thing looks less dramatic and more compromised. Even the 5th gen Camaro and the current Challenger that look like spitting images of the cars that were on turntables as concepts are significantly different when side by side as a result of making designs practical (let alone how they looked in original drawings and ideas).
So while some here may be disappointed that a car that hits the streets doesn't look exactly like pen and paper drawings, or even computer animations, production vehicles NEVER look exactly like design ideas. The realities of production, platform engineering, packing, engineering reliability, safety, and a whole host of other factors take what is pretty much a flight of fancy drawing, and turns it into a practical, operational vehicle where you can actually sit in, see out of, and enjoy.