Don't believe it. That would mean they would have had to drive 5.368 km/3,338 miles per day since release date. That's almost a whole Le Mans every day for 599 days (since release).
That means an average speed of 223km/h or 139mph without pauses.
Maybe back in the early days of grinding someone came close to such an average, but why would anyone keep it up after you've reached 20,000,000 cr. for over 1.5 years?
My bullsh#&-detectors are way into the red on this one...