I've actually watch replays from these, and on the first lap, the front two cars sometimes run with a boost of some sort. On a number of seasonals, and special events, The first lap is way faster then the second lap, which even on a rolling start doesn't make sense. After the first lap though it goes away and they drive normal. After they have built a huge lead though. Im guessing that is the way PD prefers adjusting the difficulty of those events.
That said. what car are you using? there might be a car that's far better out of the box to chose. I know I learned the hard way on that. I did a few tuner challenges in the tuner section, and I always went for the unique car. To me that is the fun in tuning. Making a Volvo wagon, or Mazda Cosmo into an awesome handling, track worthy cars was a lot of fun. And while people liked my tunes, they just didn't stack up when pitted up against the more mainstream cars, or the premium cars. Cool factor only gets you so far I guess.
I found this also to be true when running seasonals. No point in running unique or different cars. Get the most obvious car as being the best, and run that. Tune as needed and adjust the engines power to change the difficulty as you like.
