An 84-year-old Mercedes-Benz that was left forgotten in a garage for more than 60 years could fetch as much as £1.6 million at auction in September.

The one-of-a-kind car, which was only recently discovered by the original owner’s grandson, still runs flawlessly and has never been restored. Last driven in the 1950s, the car will be up for auction at Bonhams’ Goodwood Revival sale in West Sussex,  on Sept. 15.

“It was an overwhelming amazement to me that such a car existed,” said Rupert Banner, the Bonhams
specialist who worked with the Mercedes’ owner. “It’s like the holy grail of our industry to find something like it.”

The one-owner car, which does not have an odometer, is believed to have less than 100 miles on it and was “cherished” by its owner, Banner said.

“It’s like buying a car that is exactly the same as if you bought it 84 years ago,” Banner said. “It’s like a ‘time warp’ car.”

When it was first manufactured, the S- Type Mercedes-Benz Sports Tourer could reach 100 mph, making it among the world’s fastest of its time.The unidentified owner’s grandfather was one of the earliest buyers of the car when he bought it from The British Mercedes Ltd. dealership in London.

“It has literally been off the radar,” Banner told The Sun. “No one knew such an untouched and archaic [car] this old existed. It is an incredible find.”

The legendary ‘Kompressor’ — German for ‘Supercharger’ — series of the 1920s was designed by Ferdinand Porsche and its 6.8-litre engine was set in a low-slung chassis frame behind the now iconic Mercedes ‘V’radiator grille. It was first seen at the Nürburgring in 1927, where it recorded the fastest time of the day at the hands of legendary driver Rudy Carraciola.

The car, which was parked in the same garage since the 1930s, is painted a dark battleship gray, has never been restored, and even still has its original blue leather upholstery, according to the Bonhams press release.