One piece of contention is that although the media is whirling with Bugatti pushing this Chiron past 300, the media isn’t telling the whole story as it’s a lightly modified version of the Chiron not available to the public. Bugatti haven’t hidden the facts but the media have naively run away with things a little. As a feat of mastering speed they are not first, they are joining a club of a few 300mph modified production cars.
There is yet to be a genuine production car straight off the shelf so to speak to perform this task, albeit a somewhat less than useful thing for a production car to be capable of!