In a way I can sympathise with your neighbour. We had a neighbour who parked his noisy diesel van in the road by our house, every morning at 5.30am he would start it up waking everyone up and leave it running for 5minutes before driving off. Other neighbours got together and parked their cars on the road not on their driveways before the van driver got home at night forcing him off our road. It turned out he didn't live on our road and had had complaints about his van from his neighbours. Believe he now parks on yet another road......works vans can be banned in driveways by the council if tey get enough complaints....are you blocking your neighbours light? would you like someone parking a big van in front of your windows?
One of my neighbours has a huge motorhome on his drive which rarely moves. It is immediately next to the neighbour's window, although still on his own land.
His immediate neighbour complained about her loss of light and so on, and the law and council could do nothing.