I'm in the same boat, I got RBT'd 2 months ago in my car on my p's, he asked to pop the bonnet, couldn't find anything, everything is stock. So 25 minutes later, after checking exhaust, which is stock, checking tyre profile when tyres are 90%, he actually decides to serve me with a fine for my back p-plate not being visible. He came up with the fine smiling like he had accomplished something and finished with the "have a nice day". Ill never forget that smile.....
Heres where my p-plate stays because I cant sit it on the side, it flies off and cant put a p-plate holder because the plate is bent, but ive never been pulled up for it before and have not been pulled up for it after so I dunno.