They painstakingly set up the whole race to uphold certain rules, so it's fair for all - and then by the end of the movie, they destroy it all, so it becomes unfair again.
Interestingly, even with those intervals, they all arrived pretty much at the same time. They should have just declared EVERYONE a winner. The time differences wouldn't have been that big anyways - pretty close to the intervals, actually, so the lead drivers wouldn't be in that much of a better position, when everyone would really have been seconds apart from each other.
They also should have of course set up as many 'punch devices' as there were competitors, so tat QUEUING wouldn't have been a major factor in this anyway. Whoever gets to the ONLY punching device first, BY RUNNING, is somehow the winner??
WHAT??
They should have used a non-punchcard-related system anyway, because this was about CAR racing, not about WHO IS THE FASTEST RUNNER!
There should have been timer people at a certain place, and they should have taken each other's time, and written it down, and then compared to the punch card - OR SOMETHING.
I would still have liked to have seen the race results in the end, as a great payoff to the viewer, and who would have won, had they really kept up with the rules that they so painstakingly and perfectly set up earlier, so it would all be fair.
The way it was done didn't make any sense, and basically broke down the whole meaning of the so-carefully set up plot and racing rule system, completely and utterly, making the race meaningless.
On the other hand, perhaps this was the purpose - to show that it was a fun race, and that's what was important, not so much as who won.
And that made it fun for the viewer, as well. So it's all good.
By the way, who drove Seymour's car closer to the people in the end, and why?
(besides the obvious cigar lighter joke)
I mean, wasn't Seymour in the audience/group of people just seconds before?

Though this may not apply directly I believe the real life unofficial official record was set by 2 guys in a Jaguar in 1979 at 32hrs 51min, and I believe this record still stands.
-BEWARE OF JET BLAST-

Capt. Chaos drops the ticket on the ground when the woman screams for help, so it wouldn't have been in the water.
And yes, that's certainly a continuity error.
"So it goes" -Slaughterhouse Five

Well, the ticket was prob mushed when Capt. Chaos jumped into the water, but anyone else starting before the Lambo team would have won..