Ha! You mean the muffler of the bus -- err.. the cop on the left side.... !!! It also took me a while to figure it out...!
i cant see the photo, but im guessing its the same one that was shown on Top Gear with the policeman being placed so that the muffler is like his penis..
To make things worse... that guy in the advertisement is like some tub of lard.. kinda like the stupid fat but hilarious cop from the movie HOT FUZZ... lol Not your ideal cop - crime fighter..