Okay, I am curious to know of any styling element, that has appeared in one form or another on a particular make or model of vehicle (cars, trucks, buses, etc.). Not sure how to define what is a "styling element," but if I did I worry the results to my query would be limited.

The goal is to find such an element that can be found on production cars of one make (not necessarily all models of that make) for the most consecutive model years.

***Other thoughts***
I am also generally curious to learn of other elements that are identifiable with a certain brand or model, even if only used a few years. This can however lead to separate descriptions of every car ever made, which ultimately may be found on the main IMCDb site, so there is no need for repetition in this topic.
***

I can think of the Rolls-Royce "Parthenon" grille is one that would be at or near the top.


Buick's "portholes" were not continuous from 1948 to 198X, because no 1958 and 1959 models had any. The portholes, then would be 1948-1957, and 1960-198X (X=I don't know!). They reappeared around 2000 on Park Avenue, and now Lucerne and Enclave models have them.

More American examples, though this topic is for brands from any country:

Pontiac:
"Silver Streaks" chrome lines running laterally on the top side of the car, except for the roof: 1936-1956.

Split or divided grille: first appeared on 1959 models, and still in use today. (not continuous)

Oldsmobile:
two single tail lamps had been a styling trademark for as long as I can remember. I can't think of any complex arrangements like Buick or Chevrolet had.

Ford:
Perfectly round tail lamps: 1952-1957, 1959, and 1961-1964. (no 1958)
rooftop crown moulding in Crown Victoria: 1955(?)-1956, 1979-199X.
notch or cutaway in Mustangs 1964 1/2-present?

Buick: "Sweepspear" body stamping or moulding in one form or another (years?)

Cadillac: blade-type vertical tail fin and lamp assembly: 1965-present (continuous?)

Chrysler: inverted trapezoid grille 1957-1964, revived on the present generation 300.

Dodge pickup trucks: "swept-side" body stamping on bed: 1961-1971 Image

Mercedes: passenger car grille overall shape has been unchaged since the 1950s.

BMW: grille also, what is the correct word for the design shaped like a pair of kidneys?

[Throws topic to hungry wolves] Thanks!

The typical style of the BMW's, like the line around and the shape of the back part of the back side-windows, is called "Hofmeister-Linie" (-line). Mr.Hofmeister was the designer of it. The first BMW with this style was the 1500/1800 in 1961.

BMW has started with the kidney-grille as a design-element in 1933 with the 303:
http://de.wikipedia.org/wiki/BMW-Niere

In German it's always known as "Niere" - "kidney"

It's not a styling-element, more a technical detail, but Porsche has traditionally mounted the ignition-lock on the left side of the steering-wheel.

And SAAB has this (in my opinion idiotical and nervy) tradition, that you only can pull of the ignition-key, when the rear gear is shifted.

And Mercedes has the parking-brake, you have to push with the left foot.

The general shape of a Land-Rover hasn't changed in the last 60 years ... and will hopefully stay that way for the next 60!


Same is true for other models of the Land-Rover range, like bonnet of the Range Rover, roof line of the Discovery, etc.

On a smaller scale the radiator grill of Alfa-Romeos hasn't changed in decades.

The very wide C-pillar on all VW Golf.

The diagonal bar on every Volvo grille.

The Bugatti horseshoe grille.

The fluted grille top on all Daimler.

Wolseley's illuminated radiator badge.

What about Jeep seven slot grille 1942-today

Aston Martin's have had the same style air vents (on the front sides, near door) since the DB4 (48 years)

Ford:
Crown Victoria: 1980-1991. It was called the LTD Landau in 1979.
Mustang: Are you refering to that little dent behind the doors that looks like it's supposed to be a rear brake cooler? It wasn't on most third genration cars (1979-1993), but in 1987 they put a factory bodykit on the GT model (image) that sort of replicated this feature.
so that's 1964.5-1978, 1987-present (or 1994 to present if you don't count the bodykit).
The Mustang also has those 3-stripe taillights: 1964.5-

Cadillac: I was sure they abandoned them for a while during the run of the last generation Eldorados and Sevilles, but the DeVille/DTS had them all along.

Nissan Skyline/GT-R: 4 taillamps: 1968(C10)-2003(end of R34), 2007(R35)-present
The lights weren't round until the fourth generation (1973), but have been since then.

Chevrolet Corvette: Can't believe I'm the first one to think of these!
Mechanical headlights: 1963-1982, 1984-2003
quad taillights: 1961-1982, 1984-present.
Of course, there were no Corvettes in 1983, otherwise those would be continuous.

Jaguar: did they use that wide oval grill on anything between the E-type and the XJ220?

It comes to mind that there are many entire cars that have retained nearly all of their styling elements for a very long time; Jaguar XJS (1975-1996) , Jaguar XJ series (1968-present), Volkswagen Beetle (1938-2003), Porsche 911 (1964-present), Jeep Grand Cherokee and Wrangler, Hindustan Ambassador (1958-present). Let's just ignore those.

"Alpine windows" of Land Rover/Defender/Discovery
Citroens with their flat rear wheel arches
6th light window of Audi 4dr cars
Jag XJ6 and 40 and X300 with "kick" at base of C pillar
Twin headlights of BMWs