Yeah Pressure washer at the Local carwash works wonders. Gets them damn pesky bugs off too..
Is it really a problem? Did bird in question crap on your car 9 months ago and your car has been in the sun ever since?
Worse case just use Bug and Tar remover
I sware we have fugging condors where I live, Most mornings I have to spray off my windshield just to do to work. Its never the rest of the car, just the Windshield.