Those are centerlock transports nuts. That’s how they tied the car down to a trailer. They are replaced with standard BBS centerlock nuts per race.
Also…all FIA approved centerlock systems now have a socket activated safety detent that prevents the nut from backing off completely during a race. The CGT and 9R6 also have such a system that worked with their own multipoint centerlock system. Lock pins are no longer approved equipment due to pit crew forgetting to install them and having wheels fly off at ~200mph…
