Car wash mode

The manual says "The vehicle is not designed to stay in N (Neutral) for extended periods of time. It will automatically shift into P (Park)."

I'm assuming that Car Wash Mode lets you stay in N indefinitely.

Does anyone know how you can stay in N before it automatically shifts to P? Is it just based on time or are there other factors (like if the wheels are moving, if there's someone in the driver's seat).