I like fire truck shows! You should go. Not everyone has a shinny new truck but it is the history and hanging out with those like you who enjoy firetrucks that makes it all worth while.
In regular car shows, I find they do not know what class to put a firetruck into for judging or reviews. Sometimes it is a full size class or hybrid or done by age groups. It isnt much fun for me as they simply do not know anything about old fire engines and equipment so I don't have much to talk about with those folks. But at firetruck events, I just hangout with those guys and listen to their stories and look at their trucks. Old and rusty or shinny and restored, I don't care as I like them all.
Give it a shot and you might really make some new good friends to share your hobby with... JMO