It still is TECHNICALLY production. Emphasis on "technically". Its using the engine from the Centodieci, a Chiron-based road car. It's like putting the Z4's 380 hp engine in the Supra. The car also had a roll cage, but that's required (I don't know why, a crash at those speeds would kill you instantly). There were also aero mods on the car, which is where "technically" comes in. I'm sure if your pockets were big enough, Bugatti would build your Chiron with those mods on it. In fact, Bugatti owners are gonna be asking for the "record" specification now, I predict. But still. 304 miles per hour. 20 mph over the Koenigsegg Agera RS. I feel bad for my Swede boys. About this however, I'm guessing they pulled a 100-200 lbs out of it, because their's no way it did that weighing more than a Toyota truck. C&D said the car had standard Chiron tires, so I'm guessing they stripped out weight, because they had said before the car would top out a 288 before the tires exploded.
P.S I'm confident this is either the pre-production or prototype of the Chiron SS, because there is no other reason they would build this thing. I think it's the prototype, because I thought Bugatti would give it more power than 1600 hp, and maybe some more drastic aero changes. Or maybe I'm wrong.