Happens easily on all cars though, from Audis to Astons, Mazdas to McLarens. All what happens is if it's left under or near a tree, for a small seed to land on it or it doesn't even have to be a under a tree at all - a bird can drop a seed on it. It's just that most people actualy wash their cars which stops things like that happening. It's only like cleaning your house and you do clean your house . . . . . don't you ?