Nine Custom Car Terms Explained Through the Hirohata Mercury

Custom car vocabulary describes changes you can often spot before you know what they’re called. The Hirohata Mercury makes a useful guide: George and Sam Barris transformed Bob Hirohata’s slightly used 1951 Mercury into a low-slung custom, finished in 1952. Its combination of altered proportions, smoothed panels and carefully chosen details helped set a pattern for later customs.

The terms below name specific kinds of work, from reshaping body panels to removing trim. Some describe a particular alteration; others, like “lead sled,” refer to a broader style. Knowing the distinction helps explain why two cars with similar paint or accessories can still have very different custom identities.

The Hirohata Merc also marks an early chapter in the Barris brothers’ work, before their name became closely associated with screen cars such as the original Batmobile. Its lasting influence comes down to more than any single modification: the separate changes were made to work together as a complete design.

Lighting and trim built into the body

Frenched describes trim, usually a headlight or taillight, set into the body instead of sitting prominently on its surface. The surrounding metal forms a recess around the fitting, giving the area a more integrated look. Customizers also call this treatment “tunneled.” The word tells you where the component sits, rather than simply saying that it has changed.

That distinction matters when reading a custom’s design. A light can remain in its original location while its housing is reshaped and drawn into the body. The result alters the way the surrounding panel meets the lamp, making the modification visible even when the component itself is familiar.

Changing the car’s proportions

Sectioned means a horizontal strip of body has been removed so a panel is shorter in height. On the Hirohata Mercury, the front bumper guards were sectioned to keep them from interfering with the custom grille. Here, the change serves a specific design purpose: the guards had to fit the revised front end.

Sectioning is different from changing the roofline. It refers to reducing a body panel’s vertical dimension, and the amount and location of the cut shape the finished proportions. On a highly modified car, the term can apply to smaller components as well as larger sections of the body.

Chopped or chopping refers specifically to lowering the roof by taking a horizontal section out of the window pillars. That work can involve reshaping the roof or changing the angles of the pillars to make the pieces meet again. The Hirohata Merc’s roof was chopped 4 inches at the front and 7 inches at the rear. Those figures describe the change at each end; they also show why a roof chop can involve more than a simple, even cut.

From the side, the roofline has a strong effect on a car’s overall stance. Changing its height and pillar angles can make the body appear lower and alter the shape of the windows. The Hirohata Mercury’s different front and rear measurements give a concrete example of how a chop can be tailored to a particular roof profile.

Removing surface details

Nosed means the trim has been removed from the hood. It’s a concise term for a change that leaves the hood’s surface simpler. A nosed hood may be part of a larger effort to reduce brightwork across the front of a car, though the word itself refers to the hood.

Shaved describes removing trim, handles, emblems or other body adornments and filling the resulting openings for a smoother finish. On the Mercury, electronic servos wired to a button hidden in the trim pop the doors. That detail shows the practical side of the work: removing visible handles changes how the doors are opened, so the car needs another way to release them.

Decked is the trunk counterpart to nosing the hood: trim has been removed from the trunk. Together, these terms help distinguish which part of the body has been simplified. A description that says a car is shaved can refer to several details, while “nosed” and “decked” identify specific areas.

Accessories and the finished look

Appletons are bullet-like spotlights that early customizers favored, sourced from decommissioned service vehicles. The period styling detail came with its own bit of presentation advice: keep them in the down position. As with other accessories, their shape and placement contribute to the car’s appearance even when they aren’t in use.

Sombreros are Cadillac hubcaps from the 1947–52 models. Customizers used them to add a dressier finish to cars such as Chevrolets, Fords and Mercurys. The name captures their distinctive look; the parts themselves show how wheel covers could change the character of a build without altering the body.

A style defined by accumulated changes

Lead sled describes a customized car with substantial body modifications. The name points to an older finishing method: lead filler was used to smooth seams between altered sections. It refers to the extent and character of the customization, not one isolated piece of equipment or one specific cut.

That broader meaning ties the other terms together. A custom might be frenched, sectioned, nosed, shaved and decked, with a chopped roof and period accessories. Each word identifies one part of the work; “lead sled” describes the kind of car that can emerge when those changes are combined. The Hirohata Mercury remains a clear reference because its details serve a unified shape, and the vocabulary gives enthusiasts a precise way to discuss how that shape was made.

In 2017, the Hirohata Merc was added to the National Historic Vehicle Register, with information preserved at the Library of Congress. Its vocabulary still travels through custom car culture: knowing these terms makes it easier to look past the silhouette and see the decisions built into it.

This story first appeared in the March/April 2025 issue of Hagerty Drivers Club magazine. Join the club to receive the magazine and access automotive events, discounts and roadside assistance.

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