So... on my street parking used to be horrible but now we have residents parking so you can usually get a space somewhere, but it's a bit hotchpotch, there are a few houses with driveways, a business on the road with lots of cars dropping off and picking up.
Outside my house there's a run of three parking spaces available (before you hit gaps for driveways) that stretches across three houses - we're in the middle.
I have two cars, but I only ever put one outside my house, I leave the other across the road in the no man's parking bit, or find another area on the road that isn't so popular (it varies depending on what's available). My neighbour has two cars but ALWAYS has both cars outside on this little stretch of spaces and they don't move or use the cars for weeks at a time. And the other neighbour runs out into the street at every opportunity to move her car to the third space (so if we get this space it's gone as soon as we do a school run). So it means we can rarely get one of the spaces outside our house.
I don't mind this for exercise purposes but when we want to load the car to go to the tip, come back with heavy plants from garden centre, come back from school run with loads of bags and instruments etc, want to wash the car it's getting really wearing never being allowed to park outside our house. And it feels like the spaces belong to our neighbours rather than us.
WIBU if I wrote to the two car neighbour and asked them politely if they'd mind keeping one of their cars off this stretch like we do? Obviously I'd say that it's not about me creating some kind of rule, but more about common sense - if they had shopping or tired or something I'm not expecting them to not park outside their own house.
I'd go and ask in person but the man of the couple is very overbearing - negotiation is not his strong point and he's shouted me down on various other issues. Not literally shouting, just very strongly opinionated and not good at listening to others. Him and his wife are very polite though and if I put it down nicely in writing they might even be mortified to know how much inconvenience it's causing us.