Wow.
A year and 4 months, racing an hour everyday.
I doubt anyone got 500, or even 250, legitimately.
Most everyone had more than one car; if it broke, you kept going with another and another and another.
There was hardly any place to work on cars..backups were essential to keep playing on your lane.
The tracks I played at 1964-1966 were almost always full with a waiting list...most Raceways were open 9AM to Midnite.
Racing was not well organised, more likely just "line up and race 5-10 laps" for a ribbon.
I played endlessly on the tracks, rewound arms and built cars for over a year before I even bothered entering an "organised" race.
And all that was because it was an incredible fad that attracted millions and dominated the culture until it just had to burn out from its own success.
500 hours on the track was easy.