I quit going to most car shows many years ago for several reasons. Primarily, I got tired of spending hours cleaning and preparing the car for a show where it was regarded as just another old car. Around here the vast majority of vehicles are modifieds, street rods, etc. Second most of the vehicles being shown were shown at the last show and even the six shows prior to that. Third, I had boxes of trophies in the attic that had no current meaning to me. Yes, I enjoyed receiving the trophy but it quickly just became something else to dust and try to figure out how to display. Solved those problems by not going. Or if I do go to a show, drive my vehicle to the show, park it in the lot and just look over the "show" vehicles.
If you want to display a few trophies, just go to the local trophy shop and have a few made up. Use fictitious name of the event, pick a date, select a class and award title (Best of show or participants choice or sponsors choice). Then schedule the show in your driveway. Don't advertise the event as you might have some real competition and not win. Since you are the only participant, obviously you will be awarded the highest award. If someone asks about the "show" tell them it was by invitation only and you were surprised that you were asked to participate but, reluctantly attended as you didn't feel your car would be equal to the competition. "Can you imagine my surprise when I received this trophy?" You don't have to add "I can't either as it was no surprise since I sponsored the show and bought the trophy."