The 24 Hours of Le Mans is one of the most exalted races in the world, testing the endurance of teams with multi-million dollar cars and the latest technology in a grueling endurance race. The 24 Hours of LeMons, on the other hand, is extreme not because of how fast or expensive the cars are but because of how fast and expensive they aren't.
In the 24 Hours of LeMons, teams compete with beater used cars. In fact, no car in the race can cost more than $500, and teams decorate their heaps with plenty of style. The teams rotate drivers and try to complete the most laps of a race course in 24 hours. Of course, because the cars are so cheap, they also have to stop and make repairs. The 24 Hours of LeMons isn't extreme in terms of tech, speed, injury or flaming crashes, but it is extreme when it comes to the number of times people ask participants why they'd want to do something so silly.