We are lucky enough to live in a leafy village. We have 2 cars in our household, mine parks in the driveway and the other on the street outside. Parking is reasonably busy but not mad - my partner can usually park within 100m of the house.
For the last 3 weeks another car has been parked directly outside our house. It hasn't moved in that time. Our neighbour phoned the police and it isn't stolen and is registered to someone in the village but not in our street.
My partner wants to put a note on the car to the effect of thats its unfair to park there and would they mind moving it. I am of the opinion that its not our park, they are not doing anything wrong and its a bit curtain-twitcher-y to leave a note (but then I get to park on the drive!)