This is an interesting discussion, however I thought I was clear on "school property" until I read this stuff here.
I was under the impression that if you didn't touch it or let anyone else touch it then it was ok to have it in the car.
I do a lot of work on school property and always disarm before getting to the property and lock them in my portable safe. They are not touched again until I'm off the the school property.
Clarification of this is very important to me since I am on school property quite a lot.
I will tell you this, when I disarm I do not take off my holster, and during the course of the work it has become "exposed" to teachers, maintance men, SRO's (School resource officers) and the like. No one has ever said anything.