i think the reminder is a good idea but will not solve the issue if a charge is needed. i have the same issue all the time and its been going on for years.
the only place i can guarantee a charge is the Lacey City Hall area because it has 4 different plugs scattered thru out the City Hall/police station/Library area. this covers about a block in area. so no matter which one i park at and what my destination is, its not a big deal.
but have been to Costco many times and only plugged in twice with my Zenn and both times because i had to plug in, so ended up sitting there until the culprit left. and yes, i did my best to glare at them while they were loading their groceries.
i think we really need legislation and an information campaign to get the word out