After careful scientific study, and a scratch card and lottery ticket purchase later I have concluded that bird poo - on or off you - means nothing. A dirty coat perhaps..but nothing more.
Tara has a slightly different take on the matter. She feels that my research is flawed as I had wiped off the poo in the car BEFORE purchasing the tottery ticket. Had I not wiped it off, we could have been sipping drinks on a sunny island somewhere.
Life and lost opportunities...never mind.