I have ran mine through several times. The first time I used the above procedure. Just know when you open the door the parking break sets. I had the car wash attendant ready to kill me.
I have not tried it again. I don't open the door just put my foot on the brake and put it in neutral. So far so good. Why has it got to be so complicated.
If you are going through the car wash with the driver inside the vehicle, you just put it in N and stay in the car.
The problem is that the Bolt automatically exits N and goes to P when you open the driver side door. So, the car wash procedure where you put it in N and then get out of the car **will not work**. Annoying, and then solved that with this 'car wash mode' exception....if you enter N with the door cracked, you can exit the car, close the door and it will stay in N for an unspecified period (longer than a normal carwash) until you open the driver door a second time.
Sorry, but what a PITA!
Going back to the OP, if the car is stationary, you put it in 'N' and apply the parking brake (it will roll otherwise even on a slight grade) and then climb out the **passenger side door**....it will sit in N indefinitely....I have tested up to 8 hours.
This mode is useful for 'camping' in the vehicle overnight, or using the Bolt for backup power...since the DC-DC converter is active, the car can supply >1000 Watts from an inverter indefinitely.
However, the noisemaker is on in N. And you cannot open the diver side door, however, or it goes into P.
Does the noisemaker operate in 'car wash mode'? If not, I might use that trick for backup power applications, and save myself the step of pulling the fuse.
Experiment: how long will car stay in CWM?