Visitors to the first postwar London Motor Show on Oct. 27, 1948, are greeted by a surprise car that Jaguar had assembled from concept to reality in just two weeks.
The XK120 was conceived by Jaguar founder William Lyons as a limited-production loss leader -- a way to show the power and potential of the XK engine, a 130-hp six that would power Jaguar's upcoming sedans, as well as new lightweight materials, notably aluminum.
"The real reason for the XK120 was survival," said Fred Hammond, Jaguar's head of heritage. Because Lyons saw the future of the company as based on sedans, the idea was to maximize consumer appeal by building a sedan with a race car engine.
It was Jaguar's first sports car since the SS100, which went out of production in 1940.
The low price tag that Lyons gave the XK120, roughly 1,000 pounds or $1,470, along with its voluptuous, felinelike styling, made it an instant sensation.
Stunned by the public's praise, Jaguar changed plans and spent the next 18 months tooling for a production version, which would be the fastest factory-built machine on earth.
Early XK120 models came with a straight-six, 160-bhp XK engine and a body molded out of aluminum and trimmed in ash wood. Performance was exceptional: The car set speed records, and Jaguar ended up using the engine until the 1980s.
The model's name came from the 120-mph top speed Jaguar promised, which at the time made it the fastest production car in the world. Zero to 60 mph took 10 seconds, aided by the lightweight frame. By 1951, XK roadsters with their revolutionary engines and four-speed manual transmissions were averaging more than 100 mph for 24 hours on special, banked tracks across Europe.
The first 242 XK120s made had wood-framed, open-top aluminum bodies with two seats. Perceiving the design line from the front wheels, over the hood, and to the rear was like watching a rolling wave: smooth, calm, powerful.
Production switched to all-steel construction -- better for making the cars in volume -- by 1950. It eventually came in three versions: as an open two-seat roadster and later, as a "fixed-head" coupe in 1951 and a drop-head coupe in 1953.
The design soon inspired other roadsters on both sides of the Atlantic, namely the Chevrolet Corvette at its arrival, and helped cement Jaguar's reputation for decades to come.
Bloomberg contributed to this report.