Its b/c of judges. Most judges don't know squat about cars. If you are lucky, they know about THEIR FAVORITE BRAND and that is all. I've judged before and I can have a discussion with people b/c I know pretty much about all cars. I've held up announcing winners so I can make sure people in the show got a fair shot. You will also have some bias with judges.
There are also categories wild/mild etc but again, the judges are usually horrible.
For the most part at a car show, SHOW wins. Oddly I've seen STOCK cars been SHOW cars, again showing the judges either prefer a cleaner look or just didn't know what the hell they were doing.
Even with high performance vehicles in shows, they are covered with sponsor stickers, decals.
Its very tough to have a show, compete in shows, judge shows, hold shows.
Also people that compete in shows cannot ASSUME judges know everything. They better find out who the judges are and try to talk to them to explain what they did.
