The "Interceptor" proposal was the first design series to make use of the 3/8-scale model concept and to incorporate some of the ideas developed from the visit to see the P-38 Lightning. Some of the models sported an early version of the tailfin, others did not. All of them, however, were based on the single line flowing from the leading edge of the vehicle to the rear bumper. Some of the Interceptor models were even triple-prowed like the P-38, and otherwise borrowed heavily from the plane's design.

Hershey remembers working on the clay models one day in the studio in the GM engineering building and adding tailfins to a particular model of that series. When Earl came in with Nick Dreystadt, one of the top executives, he saw them and told Hershey, "Take those things off!" Being the rugged individualist that he was, Hershey left the fins on and simply covered them with a drape. Earl came back a couple days later and said the same thing: "I told you to take those things off!" Hershey just covered the fins again.

Some time later, Dreystadt came into the studio, looked at the model, and said, "Thank God, you left the fins on the car! The top brass loves them!" Earl then encouraged Hershey to leave the fins on the models wherever he wished. Tailfins had gained a secure foothold in Cadillac design.

The Interceptor series was an interesting offshoot of Cadillac styling that was never introduced to the public. Actually, two full-sized running versions of the Interceptor concept were built shortly after the war. Partly due to their aerodynamic design, their performance on the GM test track was spectacular, Hershey remembers. The engineers were especially impressed.

The problem was that when top management looked closely at the cars, they finally concluded that their design was just too advanced for the public. Harley Earl had once said, "A fundamental we have learned ... is not to step too far at a time; but every now and then we take a risk." To bring the Interceptor to production was deemed too great a risk. The Interceptor design concept thus went no further than the two prototypes that had been driven on the GM test track. Finally, they too were broken up.

The sad fact is that the Interceptor might well have become the 1948 Cadillac, but the design was judged to be too far ahead of its time. Earl therefore directed Hershey, as the head of Cadillac Design, to take a new tack -- to start over. Because the 1946 and '47 Caddys had been rehashes of the '41 and '42, it was concluded that Cadillac needed a fresh new beginning, one that would reinforce its leadership position of excellence of design.

At this crucial point, a significant event occurred. There was labor trouble at GM and where in Detroit in the early postwar years, for that matter -- effectively locking the design team out of its studio. During the work on the Interceptor, however, Hershey had bought a 60-acre farm about 48 km outside Detroit to be near the General Motors test track. In light of the lockout, he decided to move the Cadillac design team -- including his master clay sculptor, Chris Kline -- out to the farmhouse to continue design work in the basement. One of the guys even made a sign proclaiming this to be the Cadillac Design Studio (although the official designation of the team was "Special Car Design Studio"). Fortunately, there was much camaraderie in this makeshift facility -- and even more hard work.

Thus did Hershey's farmhouse become the birthplace of the befinned 1948 Cadillac. Franklin Q. Hershey, the man who just seven years later would give us the classic two-seater Ford Thunderbird, was also the man who gave us the '48 Caddy -- his boyhood dream of designing a Cadillac had come true. But it was more than that, for the '48 would set a design standard that would influence Cadillac for years.

When most car buffs talk fins, they have a specific treatment in mind and point to the '48 Cadillac as having the first. However, Bill Mitchell claimed that, strictly speaking, the '48 was not exactly the first year for Cadillac tailfins. For example, he said, you can look at the 1937 Fleetwood Series Seventy-Five convertible sedan and see that there was a "fin-like" projection on the rear fender -- even though that projection was fully chromed and was obviously a separate and distinct lamp housing attached to the fender.

But true fins are a sweep of the fender itself; sometimes the taillight is housed within it, sometimes not. The success of the '48 Cadillac tailfin was how Hershey incorporated what Mitchell himself learned from the P-38. The fin was a continuation of the flow of the bodyline from the front to the rear of the car. It was as simple and as elegant as that, but Hershey alone had the talent and insight to put it together.

The '48 Cadillac was an instant success with buyers. When dealers first saw it, however, they were apprehensive, and some were downright scared the public wouldn't like it. But any negative opinions the dealers had were soon overshadowed by the public's instant and massive demand for the car. The '48 was the spirit of the P-38 Lightning on wheels -- and it was there to be bought in any Cadillac showroom. With that beautiful line flowing through the body panels, climaxing in the elegant tailfins that gave the effect of making the car look longer, the sheer beauty and simplicity of the car's body took many an onlooker's breath away. The rounded bumpers and curved windshield only added to the car's sleek styling. In 1948, Cadillac was the luxury car to own.

Everyone wanted to copy the Caddy in whatever way they could. Mail order houses did a brisk business selling tailfins that could be mounted on the rear fenders of Fords or Chevys. Design studios around the world adopted various forms of the fin for whatever car was being facelifted. Eventually one could see fins on everything from the Henry J to a Mercedes.

Even the grille of the '48 was new, although it continued the distinctive wide cross-hatch theme. A delicate bow of chrome defined the top line of the grille, while the two inside horizontal bars ran outboard to become the upper and lower borders of the parking lights. The forward-sloping hood provided greater visibility, enhancing the low lines of the car, while the front fenders blended smoothly into the bodysides, becoming an integral part of the bodywork (rather than being "tacked on").

In spite of its fresh new look, the '48 Cadillac maintained much that was distinctive of the marque. The name in script, the goddess on the hood, "V" emblem with crest up front, eggcrate grille, massive "sombrero" wheel covers, distinctive body moldings, hardware and mascots by Chris Kline, and embryonic "Dagmar" bumper guards all shouted "Cadillac" loud and clear.

The Series Sixty-One and Sixty-Two, actually a bit shorter than the same models of the previous year, each offered a two-door fastback club coupe, or "Sedanet." The almost-a-boattail coupes of 1948-49 were arguably the most beautiful postwar fastbacks ever built. The Sixty-Ones and Sixty-Twos differed only slightly in trim -- no chrome rocker panel moldings or front fender stone shields for the Sixty-One, for example -- but shared the same sheetmetal and 126-inch wheelbase. Hershey had indeed wrought some magic, because the 50mm-narrower cars were 50mm wider inside, where buyers really appreciated it.

The limited-production Fleetwood Series Seventy-Five conservatively carried on with the '46 sheetmetal, amortizing the prewar 1941-42 dies used in the manufacture of this impressive 3454mm-long-wheelbase vehicle. Available in models which carried five people, to the nine-passenger Imperial, the Seventy-Fives were luxuriously finished both inside and out, striking awe into those who witnessed one lumbering down the boulevards of postwar America.

The design flagship of the line was the Sixty Special -- the cream of the '48 lineup. Hershey points out that the treatment of the stone guards ahead of the rear wheels on this model was a direct carry-over from the Prestone side radiators situated to the rear of the twin booms of the P-38. This inspired chrome treatment, the distinctive set of five chromed hashmark strips on the sail panel, the more elegant interior, and longer 3378mm wheelbase made the Sixty Special a much desired automobile, as it is even today.

Though retaining a narrow center pillar, the two-piece windshield on all models except the Seventy-Fives was curved, quite a novelty in 1948. And because the various models differed in height, Cadillac had to produce four different windshields for the model year.

Inside the '48, instruments were clustered quite functionally in a deep pod under the dashboard line that carried through almost to the floor on both sides. Some automotive enthusiasts have called this a "rainbow" instrument panel because of its generous sweep. Functional ducts in the front doors circulated air to the side windows and the windshield, a forward-looking feature at the time.

Despite all the new styling features, the 150-horsepower L-head V-8 and Hydra-Matic automatic transmission were carried over virtually unchanged from 1941-47. The V-8 was tough, with a distinguished record for smoothness and longevity, and as good or better than anything offered by the competition. On the minus side, it was bulky and heavy. Maurice D. Hendry, in Cadillac, Standard of the World: The Complete History, described the engine's performance and economy as "adequate." The figures quoted were a top speed of 150 kilometres per hour, 0-96.6 km/h in 16.3 seconds, and fuel economy of 16.8 L/100km at 96.6 km/h (all figures with Hydra-Matic).

The '48 Caddy didn't get into production until late February 1948, and went on sale in dealer showrooms in March. The model year thus spanned a short nine months. Demand was higher than supply, but there was only time to build 52,706 cars for the '48 model run.