I think tonioseven has it spot on. If it's the show I think it is, this is easily the case. They may not even realize they're doing it, to be honest, but I don't think a show/contest that size can find a group of judges from a modeling community so small that
don't know who made what or who's who. I fortunately attended that show since I was in the junior class, and even though Andy (from Andy's Hobbytown in B.R.) wasn't particularly active in the club, he was a good friend of mine, so I probably got some of that preferential treatment at some point
When you are at the show, be sure to talk to the people there, particularly if they're wearing club shirts. Basic modeling small talk goes a long way and they
love it if you ask them how they did stuff or for advice.
Nevertheless, your Mustang looks great. The only quibbles I can see with it are the headlights and the weathering. The weathering looks more like you put drops of wash and called it "dirty," and you could probably use some work in that area. Drybrushing helps, and for that sort of thing you just need to practice. The headlights are undoubtedly the ones from the kit, and they probably figured that with the mods you did, you could have made some better looking ones with a chrome bucket and clear lens. Or, if you intended it to be a fake, weight saving headlight looking part on a drag racer, you might've removed the chrome and resprayed it silver. And the roll bar might be made of tubing that's too big. But those are little things, really, and those other entrants didn't even wire the battery (which just looks weird) or even make a bracket for it... or the coil. How are those attached to the car, anyhow? Did they use glue on the 1:1? And you scratchbuilt (I assume) an Optima, decal and all,
and used PE tiedowns with are very fiddly. And that's just the start. Your Mustang looks fantastic, and I'd be sore too. Unfortunately, that's how it goes sometimes, just remember to (everyone, together now)
build for yourself!!!