I have done a few mods on my '06 and went to a few shows.
I was killing myself washing, wiping, shining, etc. one or two days before the show. Then I tried to miss every drop of water or speck of dust on the way there.
When I got to the show, more wiping and shining. It got to be a job.
I then realized that the changes I made to my car were for me to enjoy and not for others to judge. Everyone has their own taste on what should or shouldn't be done to a car, and that is the way it should be.
I still go to shows but it is like Andy and Shadow said, to look at what others have done to their cars, see friends, eat and enjoy the surroundings.
I have won two trophies. A second place (was beaten by a brand new Z06, no mods) and made it up by winning a first place at another show (no other cars in my class).