Aston Martins aren’t cheap, but some are worth more than others. Like this one, which could become not only the most valuable Aston ever offered for sale, but the most expensive car from any British manufacturer.

It’s called the DP215, and it’s one-of-a-kind. Far from a race-converted version of one of Aston’s road cars, the DP215 was fabricated for one purpose, and one purpose only: to race at Le Mans.

It was more streamlined, with its engine set further back in its frame, and it was fast. In fact it was the first car ever to crack the 300 km/h barrier at Le Mans, hitting a top speed of 198.6 mph down the Mulsanne Straight during qualifying.

The last racing car built under owner David Brown’s auspices, it was completed just a couple of months before the 24 Hours of Le Mans in 1963, and was driven by none other than Phil Hill in the race – alongside Belgian racer Lucien Bianchi (great uncle of the late F1 driver Jules Bianchi, who suffered a similar fate). Unfortunately Hill and Bianchi didn’t make it to the finish line, suffering from a gearbox failure only four hours into the race. But its place in the famous marque’s lore was cemented.

Now 55 years later, the car’s been exhaustively restored and reunited with its original engine. And it’s headed for the auction block. RM Sotheby’s will sell it to the highest bidder at Monterey, alongside a Ferrari 250 GTO and Le Mans-winning Ford GT40. If it falls in the upper half of its $20-25 million estimate, it could even top the $22,550,00 for which the same auctioneer sold a 1956 Aston Martin DBR1 at the same event just last year.

Photos by Simon Clay courtesy of RM Sotheby’s