Hi, thanks for your question. My name's XXXXX XXXXX I'm going to assist you with it this afternoon.
Although there is no legal right to a view and no automatic right to light, a right to light can be acquired, either because the right has been granted or because the right has been earned over time (an easement).
If it is established that a right to light through a window/aperture has been granted or acquired, an obstruction may constitute a legal "nuisance", depending on the severity of the restriction, resulting in a remedy such as an injunction to move the vehicle.
Having said that, the threshold to constitute a legal "nuisance" is high. The general rule of thumb is that 50% of the light must have been obstructed and you would probably be surprised at quite how dark a 50% reduction is. Further, whilst the courts find the 50% rule a helpful guide, they are not bound by it and each case will turn on its facts. If a vehicle is parked on adjacent land at a 90 degree angle to a window, it may not reach the 50% threshold. Nevertheless, this would need to be established by a surveyor.
You can find more information regarding rights to light from the Law Commission's recent paper, a link to which can be found here: https://www.gov.uk/government/news/law-commission-consultation-on-the-current-law-on-rights-to-light
I hope that answers your question but please do let me know if I can clarify anything.
If the vehicle is unoccupied and on private land, the local authority are going to be restricted in what they can do.
A local solicitor will be able to advise you on your options and, whilst legal action can be costly, a solicitor's letter may well be able to move matters in the right direction (which would certainly limit costs).
If you need to locate a local firm, you can use the Law Society's find a solicitor search tool here: http://solicitors.lawsociety.org.uk/
I hope that's helpful.