Bought a property with a parking space but don't always have a car parked in it. I regularly (at least weekly) see a neighbour's visitor (same one all the time and neighbour doesn't have a space) parked in my space and it gives me the rage, maybe unreasonably, but that's not the point.
There's plenty parking on the road so no need for her to use someone else's space...would it be totally unreasonable for me to stick a note under her wiper to ask her to stop parking in my space as it is in regular use by the owner?