Parking at a show. Hehehe... You don't EVEN want to get involved in that.
I've worked on every ImpalaFest from '97 to 2001 and offer this observation. We have tried parking cars by class, or by some compenent of class (that is, year, color, mod level, mileage). Half the participants park correctly but bitch about having to do so; half the participants park somewhere other than the section "assigned", then then bitch because we can't find them to judge their cars; half the participants (three halves? yeah, it's a big show...) try to park where we want them, but can't figure it out so they are upset; we won't even talk about what the fourth half does...
We had one guy suggest that we should assign individual, numbered parking spots. If you didn't park where you were supposed to, you simply wouldn't get judged. Yeah, that would go over good. <laugh>
We have some very vocal individuals who insist the only reason they go to an event like this is to park with other members of their local club. You will go absolutely nuts trying to please everyone, so you've gotta do what seems to work.
For a "judged show", like we normally run, we settled on a scheme where you park any place you want, then check in with one of our members who is responsible for your section. He turns your entry over to the judges, with notation of where you've parked, so they can come and find you without too much hassle. But that gets complicated by people who move during the show. You can't win.
Check out the drive through judging that our friends do at ImpalapaLouis. It eliminates some of the parking hassle, but it puts more pressure on the participant to line up to be judged at the appointed time, and it completely eliminates the "display" from the competition. See, you can't win!
Although pre-assigned parking sections makes it easier to find a class of cars, it doesn't seem likely that we'll go back to assigned parking sections; not for a while, at least.