Car being parked on private parking/land and no legal right

Between two set of terraced houses there is allocated parking. 67 & 69 - have a space each round the side/back of houses and then houses. No space for house 65 as they have a garage and drive way. It is then the same with the next terrace group on thsi side of street, two end terrace have no rights for parking-just middle two houses which i think are 61 & 59 The car park is being used by all houses and not enough spaces, no markings, abandoned car by house 65. I need help to get this sorted