Always best with C5Z to get the newest one w/ lowest miles. Bushings, shifter, shocks, cf hood (Z16 CE model only), all were updated as the model progressed over the years.
It'll be a challenge to be competitive with an alignment that suits a dual purpose car, unless you are willing to crawl under at the event & mess with it or own an alignment shop.
Mine is 98% autox 2% DD so I live with the aggressive alignment.
I am surprised that more guys/gals are not showing up with C5Z's, incredible value & fun factor car. I guess it's because it's not a "practical" car & thus has to be a second or third car in the garage.
As mentioned earlier in the thread an Elise and/or GT3 will often have a size advantage in autox competition depending on the course design.
Good Luck, should not be hard to find a few of these.
It's a long shot, but if I were to find a good deal on a used GT3 for next season, I would put mine up for sale, but like I said, long shot.