I reckon unfinished projects can be the most interesting to look at, and learn how others are doing things.
I'd take it if you have the energy.
Most shows let you go for the day, but be warned, sometimes they try to enforce you stay until at least a set time,eg 3 or 4 pm mainly to avoid the cars driving around when alot of spectators are present.
Price can vary, from gold coin donation to $20 or so a car, which often covers admission of passengers too.
They should let you in with it on the truck, probably best to check as you might have to unload somewhere nearby.
Take a comfy chair, and some pics of the car for us.
I hope you go and start showing off all of your hard work.