Buyers who order a Koenigsegg are encouraged to personalize their car by working directly with the company to select unique paint colors and trim materials. One customer took the customization process to the next level by commissioning the company’s little-known Aftermarket division to re-engineer a 2017 Agera RS.

Twenty-five units of the record-breaking Agera RS were available, and production ended in 2018, so it’s too late to buy one new. Instead, an owner approached the Swedish firm with a simple request: He wanted to add air vents similar to the One:1‘s to his car’s hood. From there, the project escalated into a relatively long list of upgrades.

Koenigsegg explained that after adding the pair of vents, it redesigned the carbon fiber hood and fitted additional winglets on either side of the front bumper. It then turned its attention to the back of the car, where it added an air scoop that’s also inspired by the One:1 and an updated adjustable wing controlled by the in-car software. Black paint on the logos, on the exhaust outlet, and even on the visible bolts add a finishing touch to the design.

Inside, the anonymous customer requested a digital instrument cluster named SmartCluster in Koenigsegg-speak. Borrowed from the Regera, it takes the form of a big, driver-configurable screen that neatly replaces the three digital gauges and the small clusters of warning lights fitted to the Agera RS when it was new.

Koenigsegg initially estimated that implementing the customer’s request for additional vents would take a month, but it ended up spending longer than half a year making the aforementioned changes to the Agera RS. It stopped short of revealing how much it charged the owner to re-engineer a car that cost more than $2.5 million when it was new.