The Koenigsegg One:1 sits unfinished in the factory. In just four days, it has to be on a truck to Geneva. This is how it went from unfinished to incredible megacar over the course of 96 hours.

(Full Disclosure: After driving the 2015 Porsche Macan, I borrowed a Porsche Panamera 4S, grabbed ace photog GFWilliams, and went north to Angelholm, Sweden, to see the Koenigsegg One:1 being built. While there, Christian gave us all access to the car as it was prepared for the trip to Geneva. It was cool.)

When we arrive, the One:1 isn't nearly done. The interior is empty. There is no front end. No bumpers. No roof. No scoop. The wheels are incorrect. Basically, for a company that builds around 10 cars a year, finishing the One:1 in just four more days is a tall order.

We arrived on a Saturday, and the factory was bustling like it was a Tuesday. People are crawling all over the One:1 to get everything done. It's a tall order.

Here's how the car evolved in those four days, with captions added where needed.

This is what's under the front end. Those reservoirs on the left and right front are for the hydraulic actuators that bend carbon fiber flaps under the car to create downforce.

The wing mirrors are a totally new design, created in the pursuit of ultimate aero efficiency.

While the car was fitted with regular coil springs while it was being built, Koenigsegg's plan is to save another few kilos by replacing these with a carbon fiber spring. They had just received the tooling for the spring as the car was being finished.

There's the active wing, which has rods underneath. Instead of flipping up to increase downforce, it actually flips down, which is really interesting to see in action.

This is the unpainted front bumper. Those small slats are where Koenigsegg wil add the additional aero flicks to the front end.

Here's an unfinished side panel for a One:1. Note how sculpted it is compared to the slab sides of the Agera.

While Koenigsegg isn't General Motors, they are busy. This is the final production line, where they were simultaneously working on six cars. The black and gold one in the front is the Agera S that went to Geneva.

Here's the rear suspension setup. See that pivoting three piece setup in the center? That's the antiroll bar. Christian's setup is simpler and allows more variability than the traditional setup.

That's nice. One megawatt of power, though the One:1 actually makes slightly more than a megawatt, with 1,360 horsepower.

The exhaust tip is the largest piece of 3D printed titanium in the world. In order to get the purple, heat worn edges that they wanted, Koenigsegg heat treated it with a torch to get the purple edge. It was mesmerizing to watch.

The bumper is fitted, the car is coming together.

This scene became the norm. With just 48ish hours left to get the car out the door, everyone shifted to working on the One:1.

The mechanicals are hidden, which is too bad, but the car is coming together. That's good.

Hey, it looks like a car!

This is the final stage.

And finally, on the night before it was getting shipped out to Geneva, the One:1 was completed. That's when we got this final picture. In just three days, it went from being the essence of a car to the new challenger for fastest car in the world. An incredible feat to witness.

Photo Credits: GFWilliams