You are doomed!
I have the biggest problem with cats pooping - on the front garden, drive and back garden. It is disgusting. Nothing I've tried works and I can never catch them in the act to shoo them away. The front is either a tortie, tabbie & white or a long haired b&w. The back is anyones guess .. I think a massive tabbie, black, chinchilla coloured one and possibly others. On top of that a new cat has appeared .. Looks about 4 months old and is a black long hair.