Even in chic European cities like Vienna, it’s uncommon to see a 100-year-old Rolls-Royce Silver Ghost, which has been called the most valuable car in the world. But imagine seeing more than 40 of these ultra-expensive vehicles rolling through the streets of Vienna.

Then imagine spotting more than 100 Rolls-Royce Silver Ghosts a week later in Italy, which will be the largest gathering of its kind in the world. Even more incredible is that dozens of these rare Rolls-Royce models are not pampered museum pieces and will take part in a 100-year-anniversary​ re-enactment of a historic Alpine rally.

After failing to finish the grueling Austrian Alpine Trial in 1912, British aviator and adventurer James Radley, pictured above with his Rolls-Royce Silver Ghost, was determined to complete the course as well as win awards along the way.  He did both, with a little help from champagne at the starting line.

According to Roll-Royce, Radley wrote of his 1913 departure from Brown's Hotel in London: “We must have a bottle to christen her. And there outside Brown’s was duly christened, and a glass of champagne was poured into my radiator.”

A total of 6,173 Silver Ghosts were made between 1906 and 1925, with 1,703 made in Springfield, Mass. The 1913 model had a 7.4-liter 6-cylinder engine making 50 horsepower, fed through a 4-speed manual transmission. Radley's Rolls had black wire-spoke wheels (wooden spokes were available through 1921) and gas-lit headlamps (electric lights were introduced in 1914).

Every car is worth something, but perhaps none so much as the 1906 Silver Ghost that sold for $7.1 million last July. That car was a special "Double Pullman" limousine, unlike Radley's sportier convertible.

Next month, a century later, Radley's Silver Ghost will return to Brown’s Hotel to re-create the journey along with the car’s modern-day successor: a 2013 Alpine Trial Centenary Collection Rolls-Royce Ghost that’s painted the same powder blue as Bradley’s car. (Interestingly, a similar hue is seen on all the Qatari royal family's exotic cars parked outside Harrod's.)

Rolls-Royce also outfitted the new car with a clock that displays the stages of each rally and timing as well as inlays for the front fascia and rear picnic tables that “express the topography and distances of the Alpine route.”

Both cars will be piloted by the Rolls-Royce Works Team and accompanied on the Austrian Alpine Trial by 40 Rolls-Royce Silver Ghosts, some more than 100 years old. The rally will begin in Vienna on June 14 and run through Italy, Croatia and Slovenia, navigating more than 1,800 miles on some of Europe’s most scenic but challenging mountain roads.

On June 21, the rally drivers will be joined by a group from the Rolls-Royce Enthusiasts’ Club at Riva del Garda, Italy, where the cars and their owners will gather for the largest assemblage of its kind. The Austrian Alpine Trial will terminate in the Austrian capital where it started – exactly 100 years to the day since Radley finally finished his road course.

And the champagne will flow again after the road trip at an event hosted at Vienna's Palais Pallavicini. Just maybe not into radiators this time.

[Source: Rolls-Royce]