Ahaha this is the type of question I am too embarrassed to ask, so I always hope somebody else will do it for me. Thanks!
As a matter of fact, I washed my car three times at the automatic carwash and it was always an embarrassing nightmare.
I still have no clue what are exactly the steps needed to keep the car in neutral, with no auto braking so that the rolls can freely move the car forward. And yes, I had also the car twisting for a second before the guy pushed the emergency button to stop the rolls. Nothing bad really happened, mind you, besides feeling dumb and embarrassed.
Typically, after some minutes trying to put the car in neutral, with no brakes on, the guy at the carwash just opens the door and helps me, making me feel like a 10 years old kid trying to drive a car for the first time.
So yeah, I can only remind you to turn off the parking sensors to avoid endless beeping. That's something I learned immediately.
Beside that, I always try to go through the procedure in my head before I approach the carwash, but as I said, without too much success. Let's do it together here, maybe the other guys can help us and we come up with a proper procedure:
1. Drive the car in position
2. Smile at the guy outside, pretending that you know what are you doing
3. Turn off the parking sensors
4. Put the car in Neutral
5. Disable the Parking brake
6. Make sure Auto Hold is off
7. Make sure you are not touching the brake pedal
Normally at this point something is wrong and the car does not freely move on the rolls. The annoyed guy knocks on the window trying to explain what I should do, but I don't speak well German so I panic. The guy opens the door and does something.
Any help with the procedure is really appreciated.