Bird droppings are extremely caustic, and can ruin your car's finish. They also contain grit, which can and will scratch your car's finish if you try to rub them away. Combined with a sunny day, bird droppings can harden into a substance with more sticking power than instant adhesive, and do more damage than coarse sandpaper.
Spray entire vehicle with water. Water is the closest thing to a universal solvent that we have. Although water alone will not remove the bird droppings, it will soften them so that less cleaning fluid will be necessary.
Mix cleaning fluid according to package directions. The best cleaning fluids use natural ingredients rather than inorganic, petroleum-based surfactants. Fluids containing orange or other citrus oils, witch hazel, wintergreen, or other plant-based surfactants clean well without damaging your finish.
Apply cleaning fluid to a soft cloth. Do not apply directly to your car.
Squeeze some of the fluid over the worst of the bird droppings and allow to sit for a few minutes. Wash entire car, using soft cloth and broad arm movements. Think "wax on, wax off," from the movie, "The Karate Kid." These arm movements will help keep you from having sore muscles later. This will also ensure that the same pressure and direction has been used for every part of the car, preventing streaks later.
If necessary, dip cloth into fluid one last time and pat gently at the remaining bird droppings until they are completely dissolved. Spray entire car with your hose, allowing car to drip dry. Wipe car down with a soft cloth to prevent water spots.
