Just reading through this thread, and whilst I would agree that contacting PALS is a wise step, I would personally take a slightly less gung-ho approach to doing so, and appealing to their good nature, rather than threatening them with being 'jointly and severally liable' for breaches of the Equality Act etc., as I'm not sure such an argument would be quite so clear-cut were it to get to court. The point of reasonable adjustments is to ensure that disabled people are not placed at a substantial disadvantage compared to non-disabled people - I could easily see a judge concluding that requiring all car park users to have a valid permit
* would not, at face value, place disabled people at a substantial disadvantage.
I'm not saying the Equality Act should not be mentioned, I'd just be a bit more gentle in my mentioning of it. Especially with PALS. After all, they are human beings, and are potentially more likely to seek to seek to help someone who presents a genuine story of a disabled person being caught short and now being harangued by a parking company, than someone who steams in shouting the odds and threatening legal action. A sledgehammer is not always the best tool with which to crack a nut.
*remembering the potential, entirely separate, argument of whether or not any consideration is offered to non-permit holders, and thus whether a contract has been formed at all