Soldato
Which is all lovely but still doesn't explain what the etiquette is to avoid being perceived as rude if you need to charge to 100%?
Do I perhaps need to go and explain myself to make sure the other person knows why I might need 100% before they just assume i'm being an idiot / rude for not unplugging at 80%? Put up a little sign in the car window?
The correct thing to do in that situation is give less of a **** what a random stranger thinks.