Parking madness advice

Hi, looking for advice on a issue that has been going on a while now outside my own home, we have two cars one is down the drive the other is parked outside the house with no obstruction to anyone, i have always said to people i don't mind where they park just as long as its not outside my house or blocking the drive as i'm a carer, long story short i have a neighbour who has a big discovery with a towing bar on and he reverses so far up to my bumper you can't even fit a 2p in between so how he's not hit it is beyond me, also as people might know boots on discoveries open outwards not upwards which has had him hitting my car twice with his boot door.

I can't lie i get pretty angry over it now but never used to but everyone on my street has a problem with them parking, currently have a standard Focus but imagine i owned a BMW or something and you have someone parking that close to you or letting their boot hit your car...not to mention i need my car for hospital appointments and other things.

What is the legal stance on someone parking? how much of a gap do they need to leave? if a gap is so small you cant fit fingers in it or open your boot surely this is some kind of obstruction? people might suggest talking to them but these people can't be talked to and are avoided on the street for good reason, 100% if i was to start talking to them over parking it would kick off, i have considered taking photos of them parking but they have CCTV they watch us on so i feel this would only provoke them further, i have put CCTV up as well just to cover my car from being hit again, i also shouldn't have to park all the way down my street on a hill and have to walk up and down to my house just because they want to purposely park in my spot, my street has tons of cars on with one house having 6 cars! so you can imagine parking being a nightmare already and i know with tax you can park where you want but i thought it was just common curtesy not to block someone's house or park on their bumpers.

Like i say this has been going on a while...to the point where most people on my street struggle to even park on their own street never mind outside their own house, what can i do about it or is it a case of just ignoring them and relying on them not hitting my car again? luckily i have cctv now but it clearly doesn't bother them but at least any damage would be recorded.

Just to give some context to how much of a nightmare my street actually is we'll take the top half of my street for example, top half has 3 houses each side so 6 houses all together, 1 is empty and another is a really ill person with no cars, one house has 6 cars all on the street and another has 2 long base vans and 2 cars on the street, another has 2 jeeps and a car on the street, so without my car on the street there is already 9 cars on the street with 2 vans and 2 jeeps so 13 cars to fit outside 6 houses so you can imagine how annoying it is for people constantly having all these cars parking outside their house not to mention 13 cars is before guests coming over to peoples houses....so yep a nightmare!