Get a couple of sheets of kitchen roll, fold it roughly to the size of the 'incident', if not a bit smaller. Wet the kitchen roll through under the hot tap, then put it right on the birdsh*t, just enough to let the moisture saturate it.
Give it 30 mins.
Take the kitchen roll off, and it should shift. Dry off the affected area once all the birdsh*t is removed.
Then you should see if there's any etching to the paint. A light cutting compound like T-Cut should help. Wash the car. Follow that with your usual polish and wax procedure.
