Koenigsegg, suffice it to say, has made some fast cars. Some of the fastest, quickest, most exotic in the world, in fact. But few could ever hold a candle to the ultra-exclusive One:1. And there just so happens to be one up for sale right now... but it doesn't come cheap.

The One:1 was based on the recently retired Agera, but was more extreme than any other in the series that was already more extreme than just about anything else on the road. More than a supercar or even a hypercar, Koenigsegg dubbed the One:1 the world's first "megacar."

That much it owed to its engine: the same 5.0-liter twin-turbo V8 that's powered most of Koenigsegg's creations, but augmented to develop 1,341 horsepower – a full megawatt of power. And it had over 1,000 lb-ft of torque to go with it, all channeled to the rear wheels through a seven-speed dual-clutch transmission.

That was the "power" side of the equation. The "weight" part had the Swedish manufacturer strip it down to the point that it tipped the scales at just 1,360 kilograms (just under 3,000 pounds), giving it a "perfect" power-to-weight ratio of one metric horsepower for every kilo. Hence the One:1 nameplate.

The result was a 0-62 time of just 2.8 seconds and a long slew of acceleration (and deceleration) records, including the 0-300 km/h, 300-0 km/h, 0-300-0 km/h, 0-200 mph, 200-0 mph, and 0-200-0 mph – several of which still stand today.

For better or worse, the Koenigsegg One:1 was also (nearly) as exclusive as it was fast. Only six examples were made for "public" consumption. This navy-tinted bare-carbon example was the only one delivered in right-hand drive, and it's available for purchase by SuperVettura in London. All it will take to put it in your garage is the small matter of $6 million ($7.2m with tax), making it far and away the most expensive car currently listed on JamesEdition.