"Any particular reason it says S3 tires only"?

Yes, because that's what I wrote.

Actually, I don't want any of the tire worries from last time around. When I allowed more than one type people ended up wondering if the tires were the biggest difference.
As for N tires, I took time to consider all the options and decided that for this tuner challenge N tires were not the way to go.
Regarding mods... Take it for what it says in the thread. 👍
Weight reductions, etc etc are all allowed (though not required).
Regarding judging 1 or 2 categories... You can judge all three and enter all three. Public displays of scoring and a judge approval process should help keep judges from destroying the fairness of the competition.
The special award is indeed "whatever the judge makes of it" as long as there is some merit to the claim (another reason it is important to have quality judges).
Also, speed should play a small part in the judges' scores. This sort of tuner touge challenge is more about tuning a car to handle well than to run fast laps. Think about it like this... Want fast lap times? Get a fast driver, or get more power/ less weight. However, if you want a car that feels good to drive- tune it right and use the right car. The Tuner Challenges are about creating a tuner that feels good to drive, something fun and impressive.
Hope that clears up some of the questions (although the answers to a few of them might have been in the other thread).