Wrote a huge thread trying to explain the situation but it got to long and complicated, it basically boils down to this.
Car on the left is parked outside their garage. Car in the middle is parked outside their garage. Both are in a communal spot but, it is mutually agreed that owners of the cars park outside their own garage.
Car on the right is an abandoned car and is owned buy the owner of the car the left. The abandoned car is also in a communal spot.
Communal means shared, no? Surely beneficial to all.
Is it unreasonable of car owner on the left?
NB:- although over grown the greenery on the far right is the land of the car in the middle and will be flatten and veg patch/flowers etc planted soon.