I've run into that also. Back in the early '90's a brand new '92 Crapmaro got best of something trophy at a show. Other than being detailed to the hilt, it was bone stock. WTF? Fortunately the shows around here (back when it didn't rain every freaking time a show was scheduled.............) get very few if any rice burners and Fast and Furious types. I like to call them "Slow and Delirious".
I have no problem with a tastefully done, well built ricer coming to the show but the Civics with the hubcaps removed and the coil springs heated until the suspension is on the snubbers and fart can sticking out the back,,,,,,,,,,,,,,NO WAY! To be fair, I've seen some non rice that shouldn't be there either. You know, like a clean but rotted "survivor" '83 Buick LeSabre 4 door or similar thing. Just because you put "COLLECTOR" plates on it doesn't mean it's a car to put in a show.