The Project One (or just AMG One, as some sources suggest) might just be Mercedes’ most ambitious project ever, which explains why the automaker is already behind schedule due to some powertrain adjustments.

Unlike a Formula 1 car, which can afford throttle leakage while idling at 5,000 rpm, the Project One needs to be able to idle at 1,200 rpm while also meeting all the new emissions regulations. This just goes to show that building a Formula 1 car for the street is by no means easy.

One of the lucky few who now need to work on being even more patient is 2016 Formula 1 champ Nico Rosberg, who recently posted a video about his experience customizing his own hypercar.

Rosberg and his wife were among the customers invited to Munich, where he had a chance to look over the car, while also giving his viewers another sneak peak at the interior. In the end, he even asked for outside help in choosing a color for his Project One, although he did already fancy the vehicle in grey.

Even though performance figures aren’t final, the Project One concept featured a plug-in hybrid powertrain comprised of a turbocharged 1.6-liter V6 engine and four electric motors. The total combined output was over 1,000 PS (986 HP) and it had an EV-only range of 25 km (15.5 miles).

According to Mercedes-AMG, those numbers should get you from 0 to 200 km/h (0-124 mph) in less than six seconds and on to a top speed in excess of 350 km/h (217 mph).