I will agree that the "Top 25" or whatever number can be the best way to go about doing this. I got into a warm discussion as to why my 7 year old at the time '86 Mustang 1st place was better then the guy next to me who had a '73 and was 3rd. Should we have been in the same classification - no, but that's how the organizers set it up. My car was immaculate inside and out, his - the engine compartment hadn't been cleaned for years. This tends to keep the trophy hunters at bay to some extent.

You do need some other attractions - games or mechanical competitions - to keep folks busy.

Eight hour shows - gasp!!! I've probably left more of them then stayed for handing out of those useless trophies, and of course "missed" my chance.

Goody bags - love 'em. that is if they have something useful rather then some junk that ends in the trash.

Value give aways. How much can you get the local car parts, home centers, etc to support your endeavor. A case of oil, a cordless screw driver, a dinner out