That sux man.
I 'spose at the end of the day if you wanted to fight it YOU would have to prove you didnt have the bov.
I dont belive they are allowed to touch your car, but unless you were video recording him doing it, i dont think you can do anything.
The pod filter bracket thing makes sense, but im not sure
As for your sticker, i would say you cant have any stickers unless its on the inside of the window and prolly only the "next service is due" sticker.
I'm 99.9% sure you have to have the shroud on, not only does it keep you radiator cooler but i think its some sort of saftey thing
Sorry to hear about your "harrasment" (spelling??) They all sound like pretty petty little things to get you for.......Pricks