Start To Finish: This Is How Mustangs Are Made

We sat down with some of the guys responsible for the 2015 Mustang to see what we could learn. What we came away with was a comprehensive look at the design process — turns out it’s changed less than you would think over the years, and it’s far more awesome than we ever knew.

In the beginning, there were sketches. Really. Two to three hundred of them. Virtually every designer in the company wants a crack at the new Mustang, so when Kemal Curic — the guy in charge of the car’s exterior — puts out a call for sketches, he’s immediately flooded with more than he could ever possibly use.

Kemal and his design team whittle that number down between 30 and 40, then get in touch with Larry Pelowski, who works with clay about as well as anyone on earth. He’s hand-picked a team of the best of the best in clay modeling, and it’s his job to translate all the sketches into three dimensional scale models. There’s no flashy tech at this point. Just the eyes of a clay master carving a form, with occasional input as Kemal looks over his shoulder.

Kemal is no different than other designers, and tends to talk in terms of beauty, but he’ll be the first to admit that beauty is imperfect. He considers a digital design to be “mathematically correct," whereas a beautiful line might be aerodynamically imperfect. He uses clay because a 3D printed model would be based on a perfect mathematical model. The use of tape and clay “fixes computer problems.”

Larry is insistent that clay will always be the best way of modeling, “because there are no limits.” If a change needs to be made, a designer puts some tape on the model, and the sculptors can change a line within a few hours. To hear the tape guys say it, you can get a “very mature line over a larger area” — something a "pencil can never do." As an example of how much they change things: they went through 25 different iterations of the Hofmeister Kink on the quarter window.

They don’t bother with minutiae like carving the grille; they have a digital production team that can 3D print things like that much, much more quickly.

Kemal was adamant that he wanted the Mustang to look like it was going to “bite your head off," and not appear to be smiling, like some other cars. The clay model provided a confirmation of his theory that paper was unable to do.

Then they start dealing with what they call “global surfaces," but what most of us call the “sheet metal.” They use tape on the clay to denote two different main areas: an upper “character line” that defines the shape of the car, and a secondary “highlight catcher” which becomes the reflection you see in all those glossy night shots.

Once they’ve made the scale model, they put it inside a 3D scanner to make a digital record of it. They pick the best models — for the new Mustang, there were nine — and present them to upper management.

From there, they make a trio of full-sized models that can be wrapped in vinyl so they look like real, painted cars. They're then taken outside to a courtyard, where their proverbial curb appeal is judged alongside other cars, including the competition.

Meanwhile, Doyle Lester heads up an interior team that’s busy working through the same process. Instead of the shape of the windows, they’re concerned with matters like “can we fit four gauges in the middle of the dash, or will the A/C engineering team try to kill us?”

They go through the same iterations as their external counterparts. The airplane theme in the 2015 Mustang came about because they randomly observed that the dashboard — now vertically slimmer due to the engineering team’s relocation of the passenger side airbag — looked to them like the wings of a plane.

Kemal's explanation of a project's progression is equal parts cynical, pragmatic, and funny: “The less clay and tape on the floor, the closer we’re getting.” Once they reach a point where the car is almost perfect, they 3D scan the model again, then have a CNC machine mill a 2nd one for the engineers to play with while they develop headlights and trim pieces. It’s such an involved milling process — being off by as much as a millimeter has huge visual impact — that, depending on how detailed the model is, it can take up to a week and a half just to make a single copy.

When they’re happy with it, they make a fiberglass mold of each body panel, so they can produce what they call an “inside-outside” model. At this point, they combine the, well, the inside and the outside to get a proper feel for how the proportions blend. You can be a consummate car guy and not know that the inside-outside model isn’t an actual car. [Author’s Note: I walked around it, I peered inside, and studied it intently, knowing it was the inside-outside model, and yeah, I was fooled. Kemal, Doyle and company: congrats, guys.]

From there, they make a “verification model” out of hard foam. It’s the real deal, the most accurate model that will be made. Every single team looks at it to, ahem, verify that it meets their standards. After that, it’s just a matter of fine-tuning minor pieces here and there, and on to production.

Note: At the time of publication, bits and pieces continue to evolve ahead of production.

Aaron Miller is the Rides editor for Supercompressor. He was first shocked, then unsurprised to realize how similar the car designing process is to the editing process. Follow him on Twitter, where he's definitely not artistic enough to make models.