I'm pretty sure that the software was updated some time ago to 'recognize' carwash. Both my wife and i have 3's and have not had to disable auto for well over a year.
Recently, after an LA trip, car was pretty boggin, and even though it was very lightly raining (on and off) i took to car wash anyhow. Wipers were in auto and wipimg, but when i approached wash entrance they stopped, stayed off during wash and then as i exited, they wiped as it was drizzling. Anectdotal i know, but very consistent.