You can also try placing rubber toy snakes on the ground around the area that your parked. (Just make sure you don't mistake a real one for one of your fakes,
and tell the wife of your plans or she might kill you!) Have them in plain view. I would suggest picking up the colorful snakes that aren't realistic like pink, orange, blue they should work with the birds. I had this problem and then my brother told me he used them in his driveway to keep birds from pooping on his cars and RV. I tired it and it actually worked, birds are afraid of what they think will eat them. You can find these in a toy store, Walmart and even at some dollar stores. Good luck!