i used to have a show car
http://www.caromain.com/id/uncguy i hope that link works. 7 shows from MD to GA on the east coast. took 1st in all of them. judges look at little things. clean the INSIDE of your wheels, if the face is clean and the inside is all black and dirty it just looks like crap. make sure to wipe down your door sills and the painted inside portion of the door like when you open it, the underside of the door, clean the undercarriage as much as possible, some judges have a mirror on a stick that they stick under the car. ummm what else....clean your hood, the motor, the firewall where its painted, stay around the truck when its getting judged, politely ask if they have any questions about the vehicle you can answer for them, clean the inside of your fenderwells, wash and wax the truck really well, do NOT put on tire shine.
when you get to the show spray the truck with a quick wax and use a microfiber cloth to clean it up, THEN USE TIRESHINE. if you put it on and then drive to the show it may spit up all over the paint, also evenly wipe down the inside of the wheel wells and the frame with tireshine where they can be easily seen to give it a nice black look, umm other than that its just really your truck vs who ever else is in the show, but i'll be damned if im loosing cause my ride is dirty

whew hope that helps!!!